freebsd-skq/sys/vm/vm_contig.c

394 lines
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/*-
* Copyright (c) 1991 Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91
*/
/*-
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
2003-06-11 23:50:51 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/proc.h>
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
#include <sys/kernel.h>
#include <sys/linker_set.h>
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_pager.h>
#include <vm/vm_phys.h>
#include <vm/vm_extern.h>
static int
vm_contig_launder_page(vm_page_t m, vm_page_t *next)
{
vm_object_t object;
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
vm_page_t m_tmp;
struct vnode *vp;
struct mount *mp;
int vfslocked;
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
vm_page_lock_assert(m, MA_OWNED);
object = m->object;
if (!VM_OBJECT_TRYLOCK(object) &&
!vm_pageout_fallback_object_lock(m, next)) {
vm_page_unlock(m);
VM_OBJECT_UNLOCK(object);
return (EAGAIN);
}
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
if (vm_page_sleep_if_busy(m, TRUE, "vpctw0")) {
VM_OBJECT_UNLOCK(object);
vm_page_lock_queues();
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
return (EBUSY);
}
vm_page_test_dirty(m);
if (m->dirty == 0 && m->hold_count == 0)
pmap_remove_all(m);
if (m->dirty != 0) {
vm_page_unlock(m);
if ((object->flags & OBJ_DEAD) != 0) {
VM_OBJECT_UNLOCK(object);
return (EAGAIN);
}
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
if (object->type == OBJT_VNODE) {
vm_page_unlock_queues();
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
vp = object->handle;
vm_object_reference_locked(object);
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
VM_OBJECT_UNLOCK(object);
(void) vn_start_write(vp, &mp, V_WAIT);
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
VM_OBJECT_LOCK(object);
vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
VM_OBJECT_UNLOCK(object);
VOP_UNLOCK(vp, 0);
VFS_UNLOCK_GIANT(vfslocked);
vm_object_deallocate(object);
vn_finished_write(mp);
vm_page_lock_queues();
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
return (0);
} else if (object->type == OBJT_SWAP ||
object->type == OBJT_DEFAULT) {
vm_page_unlock_queues();
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
m_tmp = m;
vm_pageout_flush(&m_tmp, 1, VM_PAGER_PUT_SYNC, 0, NULL);
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
VM_OBJECT_UNLOCK(object);
vm_page_lock_queues();
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
return (0);
}
} else {
if (m->hold_count == 0)
vm_page_cache(m);
vm_page_unlock(m);
}
VM_OBJECT_UNLOCK(object);
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
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return (0);
}
static int
vm_contig_launder(int queue, vm_paddr_t low, vm_paddr_t high)
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
{
vm_page_t m, next;
vm_paddr_t pa;
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
int error;
TAILQ_FOREACH_SAFE(m, &vm_page_queues[queue].pl, pageq, next) {
/* Skip marker pages */
if ((m->flags & PG_MARKER) != 0)
continue;
pa = VM_PAGE_TO_PHYS(m);
if (pa < low || pa + PAGE_SIZE > high)
continue;
if (!vm_pageout_page_lock(m, &next)) {
vm_page_unlock(m);
continue;
}
KASSERT(m->queue == queue,
("vm_contig_launder: page %p's queue is not %d", m, queue));
error = vm_contig_launder_page(m, &next);
vm_page_lock_assert(m, MA_NOTOWNED);
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
if (error == 0)
return (TRUE);
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
if (error == EBUSY)
return (FALSE);
}
return (FALSE);
}
/*
* Frees the given physically contiguous pages.
*
* N.B.: Any pages with PG_ZERO set must, in fact, be zero filled.
*/
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
static void
vm_page_release_contig(vm_page_t m, vm_pindex_t count)
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
{
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
while (count--) {
/* Leave PG_ZERO unchanged. */
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
vm_page_free_toq(m);
m++;
}
}
/*
* Increase the number of cached pages.
*/
void
vm_contig_grow_cache(int tries, vm_paddr_t low, vm_paddr_t high)
{
int actl, actmax, inactl, inactmax;
vm_page_lock_queues();
inactl = 0;
inactmax = tries < 1 ? 0 : cnt.v_inactive_count;
actl = 0;
actmax = tries < 2 ? 0 : cnt.v_active_count;
again:
if (inactl < inactmax && vm_contig_launder(PQ_INACTIVE, low, high)) {
inactl++;
goto again;
}
if (actl < actmax && vm_contig_launder(PQ_ACTIVE, low, high)) {
actl++;
goto again;
}
vm_page_unlock_queues();
}
/*
* Allocates a region from the kernel address map and pages within the
* specified physical address range to the kernel object, creates a wired
* mapping from the region to these pages, and returns the region's starting
* virtual address. The allocated pages are not necessarily physically
* contiguous. If M_ZERO is specified through the given flags, then the pages
* are zeroed before they are mapped.
*/
vm_offset_t
kmem_alloc_attr(vm_map_t map, vm_size_t size, int flags, vm_paddr_t low,
vm_paddr_t high, vm_memattr_t memattr)
{
vm_object_t object = kernel_object;
vm_offset_t addr, i, offset;
vm_page_t m;
int tries;
size = round_page(size);
vm_map_lock(map);
if (vm_map_findspace(map, vm_map_min(map), size, &addr)) {
vm_map_unlock(map);
return (0);
}
offset = addr - VM_MIN_KERNEL_ADDRESS;
vm_object_reference(object);
vm_map_insert(map, object, offset, addr, addr + size, VM_PROT_ALL,
VM_PROT_ALL, 0);
VM_OBJECT_LOCK(object);
for (i = 0; i < size; i += PAGE_SIZE) {
tries = 0;
retry:
m = vm_phys_alloc_contig(1, low, high, PAGE_SIZE, 0);
if (m == NULL) {
if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) {
VM_OBJECT_UNLOCK(object);
vm_map_unlock(map);
vm_contig_grow_cache(tries, low, high);
vm_map_lock(map);
VM_OBJECT_LOCK(object);
goto retry;
}
while (i != 0) {
i -= PAGE_SIZE;
m = vm_page_lookup(object, OFF_TO_IDX(offset +
i));
vm_page_free(m);
}
VM_OBJECT_UNLOCK(object);
vm_map_delete(map, addr, addr + size);
vm_map_unlock(map);
return (0);
}
if (memattr != VM_MEMATTR_DEFAULT)
pmap_page_set_memattr(m, memattr);
vm_page_insert(m, object, OFF_TO_IDX(offset + i));
if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
pmap_zero_page(m);
m->valid = VM_PAGE_BITS_ALL;
}
VM_OBJECT_UNLOCK(object);
vm_map_unlock(map);
vm_map_wire(map, addr, addr + size, VM_MAP_WIRE_SYSTEM |
VM_MAP_WIRE_NOHOLES);
return (addr);
}
/*
* Allocates a region from the kernel address map, inserts the
* given physically contiguous pages into the kernel object,
* creates a wired mapping from the region to the pages, and
* returns the region's starting virtual address. If M_ZERO is
* specified through the given flags, then the pages are zeroed
* before they are mapped.
*/
static vm_offset_t
Add support to the virtual memory system for configuring machine- dependent memory attributes: Rename vm_cache_mode_t to vm_memattr_t. The new name reflects the fact that there are machine-dependent memory attributes that have nothing to do with controlling the cache's behavior. Introduce vm_object_set_memattr() for setting the default memory attributes that will be given to an object's pages. Introduce and use pmap_page_{get,set}_memattr() for getting and setting a page's machine-dependent memory attributes. Add full support for these functions on amd64 and i386 and stubs for them on the other architectures. The function pmap_page_set_memattr() is also responsible for any other machine-dependent aspects of changing a page's memory attributes, such as flushing the cache or updating the direct map. The uses include kmem_alloc_contig(), vm_page_alloc(), and the device pager: kmem_alloc_contig() can now be used to allocate kernel memory with non-default memory attributes on amd64 and i386. vm_page_alloc() and the device pager will set the memory attributes for the real or fictitious page according to the object's default memory attributes. Update the various pmap functions on amd64 and i386 that map pages to incorporate each page's memory attributes in the mapping. Notes: (1) Inherent to this design are safety features that prevent the specification of inconsistent memory attributes by different mappings on amd64 and i386. In addition, the device pager provides a warning when a device driver creates a fictitious page with memory attributes that are inconsistent with the real page that the fictitious page is an alias for. (2) Storing the machine-dependent memory attributes for amd64 and i386 as a dedicated "int" in "struct md_page" represents a compromise between space efficiency and the ease of MFCing these changes to RELENG_7. In collaboration with: jhb Approved by: re (kib)
2009-07-12 23:31:20 +00:00
contigmapping(vm_map_t map, vm_size_t size, vm_page_t m, vm_memattr_t memattr,
int flags)
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
{
vm_object_t object = kernel_object;
vm_offset_t addr, tmp_addr;
vm_map_lock(map);
if (vm_map_findspace(map, vm_map_min(map), size, &addr)) {
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
vm_map_unlock(map);
return (0);
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
}
vm_object_reference(object);
vm_map_insert(map, object, addr - VM_MIN_KERNEL_ADDRESS,
addr, addr + size, VM_PROT_ALL, VM_PROT_ALL, 0);
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
vm_map_unlock(map);
VM_OBJECT_LOCK(object);
for (tmp_addr = addr; tmp_addr < addr + size; tmp_addr += PAGE_SIZE) {
Add support to the virtual memory system for configuring machine- dependent memory attributes: Rename vm_cache_mode_t to vm_memattr_t. The new name reflects the fact that there are machine-dependent memory attributes that have nothing to do with controlling the cache's behavior. Introduce vm_object_set_memattr() for setting the default memory attributes that will be given to an object's pages. Introduce and use pmap_page_{get,set}_memattr() for getting and setting a page's machine-dependent memory attributes. Add full support for these functions on amd64 and i386 and stubs for them on the other architectures. The function pmap_page_set_memattr() is also responsible for any other machine-dependent aspects of changing a page's memory attributes, such as flushing the cache or updating the direct map. The uses include kmem_alloc_contig(), vm_page_alloc(), and the device pager: kmem_alloc_contig() can now be used to allocate kernel memory with non-default memory attributes on amd64 and i386. vm_page_alloc() and the device pager will set the memory attributes for the real or fictitious page according to the object's default memory attributes. Update the various pmap functions on amd64 and i386 that map pages to incorporate each page's memory attributes in the mapping. Notes: (1) Inherent to this design are safety features that prevent the specification of inconsistent memory attributes by different mappings on amd64 and i386. In addition, the device pager provides a warning when a device driver creates a fictitious page with memory attributes that are inconsistent with the real page that the fictitious page is an alias for. (2) Storing the machine-dependent memory attributes for amd64 and i386 as a dedicated "int" in "struct md_page" represents a compromise between space efficiency and the ease of MFCing these changes to RELENG_7. In collaboration with: jhb Approved by: re (kib)
2009-07-12 23:31:20 +00:00
if (memattr != VM_MEMATTR_DEFAULT)
pmap_page_set_memattr(m, memattr);
vm_page_insert(m, object,
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS));
if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
pmap_zero_page(m);
m->valid = VM_PAGE_BITS_ALL;
m++;
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
}
VM_OBJECT_UNLOCK(object);
vm_map_wire(map, addr, addr + size,
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
return (addr);
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
}
void *
contigmalloc(
unsigned long size, /* should be size_t here and for malloc() */
struct malloc_type *type,
int flags,
vm_paddr_t low,
vm_paddr_t high,
unsigned long alignment,
unsigned long boundary)
{
void *ret;
ret = (void *)kmem_alloc_contig(kernel_map, size, flags, low, high,
Add support to the virtual memory system for configuring machine- dependent memory attributes: Rename vm_cache_mode_t to vm_memattr_t. The new name reflects the fact that there are machine-dependent memory attributes that have nothing to do with controlling the cache's behavior. Introduce vm_object_set_memattr() for setting the default memory attributes that will be given to an object's pages. Introduce and use pmap_page_{get,set}_memattr() for getting and setting a page's machine-dependent memory attributes. Add full support for these functions on amd64 and i386 and stubs for them on the other architectures. The function pmap_page_set_memattr() is also responsible for any other machine-dependent aspects of changing a page's memory attributes, such as flushing the cache or updating the direct map. The uses include kmem_alloc_contig(), vm_page_alloc(), and the device pager: kmem_alloc_contig() can now be used to allocate kernel memory with non-default memory attributes on amd64 and i386. vm_page_alloc() and the device pager will set the memory attributes for the real or fictitious page according to the object's default memory attributes. Update the various pmap functions on amd64 and i386 that map pages to incorporate each page's memory attributes in the mapping. Notes: (1) Inherent to this design are safety features that prevent the specification of inconsistent memory attributes by different mappings on amd64 and i386. In addition, the device pager provides a warning when a device driver creates a fictitious page with memory attributes that are inconsistent with the real page that the fictitious page is an alias for. (2) Storing the machine-dependent memory attributes for amd64 and i386 as a dedicated "int" in "struct md_page" represents a compromise between space efficiency and the ease of MFCing these changes to RELENG_7. In collaboration with: jhb Approved by: re (kib)
2009-07-12 23:31:20 +00:00
alignment, boundary, VM_MEMATTR_DEFAULT);
if (ret != NULL)
malloc_type_allocated(type, round_page(size));
return (ret);
}
vm_offset_t
kmem_alloc_contig(vm_map_t map, vm_size_t size, int flags, vm_paddr_t low,
vm_paddr_t high, unsigned long alignment, unsigned long boundary,
Add support to the virtual memory system for configuring machine- dependent memory attributes: Rename vm_cache_mode_t to vm_memattr_t. The new name reflects the fact that there are machine-dependent memory attributes that have nothing to do with controlling the cache's behavior. Introduce vm_object_set_memattr() for setting the default memory attributes that will be given to an object's pages. Introduce and use pmap_page_{get,set}_memattr() for getting and setting a page's machine-dependent memory attributes. Add full support for these functions on amd64 and i386 and stubs for them on the other architectures. The function pmap_page_set_memattr() is also responsible for any other machine-dependent aspects of changing a page's memory attributes, such as flushing the cache or updating the direct map. The uses include kmem_alloc_contig(), vm_page_alloc(), and the device pager: kmem_alloc_contig() can now be used to allocate kernel memory with non-default memory attributes on amd64 and i386. vm_page_alloc() and the device pager will set the memory attributes for the real or fictitious page according to the object's default memory attributes. Update the various pmap functions on amd64 and i386 that map pages to incorporate each page's memory attributes in the mapping. Notes: (1) Inherent to this design are safety features that prevent the specification of inconsistent memory attributes by different mappings on amd64 and i386. In addition, the device pager provides a warning when a device driver creates a fictitious page with memory attributes that are inconsistent with the real page that the fictitious page is an alias for. (2) Storing the machine-dependent memory attributes for amd64 and i386 as a dedicated "int" in "struct md_page" represents a compromise between space efficiency and the ease of MFCing these changes to RELENG_7. In collaboration with: jhb Approved by: re (kib)
2009-07-12 23:31:20 +00:00
vm_memattr_t memattr)
{
vm_offset_t ret;
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
vm_page_t pages;
unsigned long npgs;
int tries;
size = round_page(size);
npgs = size >> PAGE_SHIFT;
tries = 0;
retry:
Add support to the virtual memory system for configuring machine- dependent memory attributes: Rename vm_cache_mode_t to vm_memattr_t. The new name reflects the fact that there are machine-dependent memory attributes that have nothing to do with controlling the cache's behavior. Introduce vm_object_set_memattr() for setting the default memory attributes that will be given to an object's pages. Introduce and use pmap_page_{get,set}_memattr() for getting and setting a page's machine-dependent memory attributes. Add full support for these functions on amd64 and i386 and stubs for them on the other architectures. The function pmap_page_set_memattr() is also responsible for any other machine-dependent aspects of changing a page's memory attributes, such as flushing the cache or updating the direct map. The uses include kmem_alloc_contig(), vm_page_alloc(), and the device pager: kmem_alloc_contig() can now be used to allocate kernel memory with non-default memory attributes on amd64 and i386. vm_page_alloc() and the device pager will set the memory attributes for the real or fictitious page according to the object's default memory attributes. Update the various pmap functions on amd64 and i386 that map pages to incorporate each page's memory attributes in the mapping. Notes: (1) Inherent to this design are safety features that prevent the specification of inconsistent memory attributes by different mappings on amd64 and i386. In addition, the device pager provides a warning when a device driver creates a fictitious page with memory attributes that are inconsistent with the real page that the fictitious page is an alias for. (2) Storing the machine-dependent memory attributes for amd64 and i386 as a dedicated "int" in "struct md_page" represents a compromise between space efficiency and the ease of MFCing these changes to RELENG_7. In collaboration with: jhb Approved by: re (kib)
2009-07-12 23:31:20 +00:00
pages = vm_phys_alloc_contig(npgs, low, high, alignment, boundary);
if (pages == NULL) {
if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) {
vm_contig_grow_cache(tries, low, high);
tries++;
goto retry;
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
}
ret = 0;
} else {
Add support to the virtual memory system for configuring machine- dependent memory attributes: Rename vm_cache_mode_t to vm_memattr_t. The new name reflects the fact that there are machine-dependent memory attributes that have nothing to do with controlling the cache's behavior. Introduce vm_object_set_memattr() for setting the default memory attributes that will be given to an object's pages. Introduce and use pmap_page_{get,set}_memattr() for getting and setting a page's machine-dependent memory attributes. Add full support for these functions on amd64 and i386 and stubs for them on the other architectures. The function pmap_page_set_memattr() is also responsible for any other machine-dependent aspects of changing a page's memory attributes, such as flushing the cache or updating the direct map. The uses include kmem_alloc_contig(), vm_page_alloc(), and the device pager: kmem_alloc_contig() can now be used to allocate kernel memory with non-default memory attributes on amd64 and i386. vm_page_alloc() and the device pager will set the memory attributes for the real or fictitious page according to the object's default memory attributes. Update the various pmap functions on amd64 and i386 that map pages to incorporate each page's memory attributes in the mapping. Notes: (1) Inherent to this design are safety features that prevent the specification of inconsistent memory attributes by different mappings on amd64 and i386. In addition, the device pager provides a warning when a device driver creates a fictitious page with memory attributes that are inconsistent with the real page that the fictitious page is an alias for. (2) Storing the machine-dependent memory attributes for amd64 and i386 as a dedicated "int" in "struct md_page" represents a compromise between space efficiency and the ease of MFCing these changes to RELENG_7. In collaboration with: jhb Approved by: re (kib)
2009-07-12 23:31:20 +00:00
ret = contigmapping(map, size, pages, memattr, flags);
if (ret == 0)
vm_page_release_contig(pages, npgs);
Reimplement contigmalloc(9) with an algorithm which stands a greatly- improved chance of working despite pressure from running programs. Instead of trying to throw a bunch of pages out to swap and hope for the best, only a range that can potentially fulfill contigmalloc(9)'s request will have its contents paged out (potentially, not forcibly) at a time. The new contigmalloc operation still operates in three passes, but it could potentially be tuned to more or less. The first pass only looks at pages in the cache and free pages, so they would be thrown out without having to block. If this is not enough, the subsequent passes page out any unwired memory. To combat memory pressure refragmenting the section of memory being laundered, each page is removed from the systems' free memory queue once it has been freed so that blocking later doesn't cause the memory laundered so far to get reallocated. The page-out operations are now blocking, as it would make little sense to try to push out a page, then get its status immediately afterward to remove it from the available free pages queue, if it's unlikely to have been freed. Another change is that if KVA allocation fails, the allocated memory segment will be freed and not leaked. There is a sysctl/tunable, defaulting to on, which causes the old contigmalloc() algorithm to be used. Nonetheless, I have been using vm.old_contigmalloc=0 for over a month. It is safe to switch at run-time to see the difference it makes. A new interface has been used which does not require mapping the allocated pages into KVA: vm_page.h functions vm_page_alloc_contig() and vm_page_release_contig(). These are what vm.old_contigmalloc=0 uses internally, so the sysctl/tunable does not affect their operation. When using the contigmalloc(9) and contigfree(9) interfaces, memory is now tracked with malloc(9) stats. Several functions have been exported from kern_malloc.c to allow other subsystems to use these statistics, as well. This invalidates the BUGS section of the contigmalloc(9) manpage.
2004-07-19 06:21:27 +00:00
}
return (ret);
}
void
contigfree(void *addr, unsigned long size, struct malloc_type *type)
{
kmem_free(kernel_map, (vm_offset_t)addr, size);
2009-06-05 16:55:10 +00:00
malloc_type_freed(type, round_page(size));
}