Introduce vm_reserv_reclaim_contig(). This function is used by

contigmalloc(9) as a last resort to steal pages from an inactive,
partially-used superpage reservation.

Rename vm_reserv_reclaim() to vm_reserv_reclaim_inactive() and
refactor it so that a separate subroutine is responsible for breaking
the selected reservation.  This subroutine is also used by
vm_reserv_reclaim_contig().
This commit is contained in:
alc 2008-04-06 18:09:28 +00:00
parent 254de061de
commit 2f4904816f
4 changed files with 99 additions and 25 deletions

View File

@ -1072,7 +1072,7 @@ vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
m = vm_phys_alloc_pages(object != NULL ?
VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0);
#if VM_NRESERVLEVEL > 0
if (m == NULL && vm_reserv_reclaim()) {
if (m == NULL && vm_reserv_reclaim_inactive()) {
m = vm_phys_alloc_pages(object != NULL ?
VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT,
0);

View File

@ -54,6 +54,7 @@ __FBSDID("$FreeBSD$");
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_phys.h>
#include <vm/vm_reserv.h>
struct vm_freelist {
struct pglist pl;
@ -607,6 +608,9 @@ vm_phys_alloc_contig(unsigned long npages, vm_paddr_t low, vm_paddr_t high,
/* Compute the queue that is the best fit for npages. */
for (order = 0; (1 << order) < npages; order++);
mtx_lock(&vm_page_queue_free_mtx);
#if VM_NRESERVLEVEL > 0
retry:
#endif
for (flind = 0; flind < vm_nfreelists; flind++) {
for (oind = min(order, VM_NFREEORDER - 1); oind < VM_NFREEORDER; oind++) {
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
@ -664,6 +668,10 @@ vm_phys_alloc_contig(unsigned long npages, vm_paddr_t low, vm_paddr_t high,
}
}
}
#if VM_NRESERVLEVEL > 0
if (vm_reserv_reclaim_contig(size, low, high, alignment, boundary))
goto retry;
#endif
mtx_unlock(&vm_page_queue_free_mtx);
return (NULL);
done:

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@ -1,6 +1,6 @@
/*-
* Copyright (c) 2002-2006 Rice University
* Copyright (c) 2007 Alan L. Cox <alc@cs.rice.edu>
* Copyright (c) 2007-2008 Alan L. Cox <alc@cs.rice.edu>
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Alan L. Cox,
@ -170,6 +170,7 @@ static vm_reserv_t vm_reserv_from_page(vm_page_t m);
static boolean_t vm_reserv_has_pindex(vm_reserv_t rv,
vm_pindex_t pindex);
static void vm_reserv_populate(vm_reserv_t rv);
static void vm_reserv_reclaim(vm_reserv_t rv);
/*
* Describes the current state of the partially-populated reservation queue.
@ -567,6 +568,37 @@ vm_reserv_reactivate_page(vm_page_t m)
return (TRUE);
}
/*
* Breaks the given partially-populated reservation, releasing its cached and
* free pages to the physical memory allocator.
*
* The free page queue lock must be held.
*/
static void
vm_reserv_reclaim(vm_reserv_t rv)
{
int i;
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
KASSERT(rv->inpartpopq,
("vm_reserv_reclaim: reserv %p's inpartpopq is corrupted", rv));
TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq);
rv->inpartpopq = FALSE;
KASSERT(rv->object != NULL,
("vm_reserv_reclaim: reserv %p is free", rv));
LIST_REMOVE(rv, objq);
rv->object = NULL;
for (i = 0; i < VM_LEVEL_0_NPAGES; i++) {
if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0)
vm_phys_free_pages(&rv->pages[i], 0);
else
rv->popcnt--;
}
KASSERT(rv->popcnt == 0,
("vm_reserv_reclaim: reserv %p's popcnt is corrupted", rv));
vm_reserv_reclaimed++;
}
/*
* Breaks the reservation at the head of the partially-populated reservation
* queue, releasing its cached and free pages to the physical memory
@ -575,33 +607,64 @@ vm_reserv_reactivate_page(vm_page_t m)
* The free page queue lock must be held.
*/
boolean_t
vm_reserv_reclaim(void)
vm_reserv_reclaim_inactive(void)
{
vm_reserv_t rv;
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
if ((rv = TAILQ_FIRST(&vm_rvq_partpop)) != NULL) {
vm_reserv_reclaim(rv);
return (TRUE);
}
return (FALSE);
}
/*
* Searches the partially-populated reservation queue for the least recently
* active reservation with unused pages, i.e., cached or free, that satisfy the
* given request for contiguous physical memory. If a satisfactory reservation
* is found, it is broken. Returns TRUE if a reservation is broken and FALSE
* otherwise.
*
* The free page queue lock must be held.
*/
boolean_t
vm_reserv_reclaim_contig(vm_paddr_t size, vm_paddr_t low, vm_paddr_t high,
unsigned long alignment, unsigned long boundary)
{
vm_paddr_t pa, pa_length;
vm_reserv_t rv;
int i;
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
if ((rv = TAILQ_FIRST(&vm_rvq_partpop)) != NULL) {
KASSERT(rv->inpartpopq,
("vm_reserv_reclaim: reserv %p's inpartpopq is corrupted",
rv));
TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq);
rv->inpartpopq = FALSE;
KASSERT(rv->object != NULL,
("vm_reserv_reclaim: reserv %p is free", rv));
LIST_REMOVE(rv, objq);
rv->object = NULL;
for (i = 0; i < VM_LEVEL_0_NPAGES; i++) {
if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0)
vm_phys_free_pages(&rv->pages[i], 0);
else
rv->popcnt--;
if (size > VM_LEVEL_0_SIZE - PAGE_SIZE)
return (FALSE);
TAILQ_FOREACH(rv, &vm_rvq_partpop, partpopq) {
pa = VM_PAGE_TO_PHYS(&rv->pages[VM_LEVEL_0_NPAGES - 1]);
if (pa + PAGE_SIZE - size < low) {
/* this entire reservation is too low; go to next */
continue;
}
KASSERT(rv->popcnt == 0,
("vm_reserv_reclaim: reserv %p's popcnt is corrupted",
rv));
vm_reserv_reclaimed++;
return (TRUE);
pa_length = 0;
for (i = 0; i < VM_LEVEL_0_NPAGES; i++)
if ((rv->pages[i].flags & (PG_CACHED | PG_FREE)) != 0) {
pa_length += PAGE_SIZE;
if (pa_length == PAGE_SIZE) {
pa = VM_PAGE_TO_PHYS(&rv->pages[i]);
if (pa + size > high) {
/* skip to next reservation */
break;
} else if (pa < low ||
(pa & (alignment - 1)) != 0 ||
((pa ^ (pa + size - 1)) &
~(boundary - 1)) != 0)
pa_length = 0;
} else if (pa_length >= size) {
vm_reserv_reclaim(rv);
return (TRUE);
}
} else
pa_length = 0;
}
return (FALSE);
}

View File

@ -1,6 +1,6 @@
/*-
* Copyright (c) 2002-2006 Rice University
* Copyright (c) 2007 Alan L. Cox <alc@cs.rice.edu>
* Copyright (c) 2007-2008 Alan L. Cox <alc@cs.rice.edu>
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Alan L. Cox,
@ -48,7 +48,10 @@ boolean_t vm_reserv_free_page(vm_page_t m);
void vm_reserv_init(void);
int vm_reserv_level_iffullpop(vm_page_t m);
boolean_t vm_reserv_reactivate_page(vm_page_t m);
boolean_t vm_reserv_reclaim(void);
boolean_t vm_reserv_reclaim_contig(vm_paddr_t size, vm_paddr_t low,
vm_paddr_t high, unsigned long alignment,
unsigned long boundary);
boolean_t vm_reserv_reclaim_inactive(void);
void vm_reserv_rename(vm_page_t m, vm_object_t new_object,
vm_object_t old_object, vm_pindex_t old_object_offset);
vm_paddr_t vm_reserv_startup(vm_offset_t *vaddr, vm_paddr_t end,