freebsd-skq/sys/vm/vm_extern.h
Konstantin Belousov 8a945d109c Reintroduce the r196640, after fixing the problem with my testing.
Remove the altkstacks, instead instantiate threads with kernel stack
allocated with the right size from the start. For the thread that has
kernel stack cached, verify that requested stack size is equial to the
actual, and reallocate the stack if sizes differ [1].

This fixes the bug introduced by r173361 that was committed several days
after r173004 and consisted of kthread_add(9) ignoring the non-default
kernel stack size.

Also, r173361 removed the caching of the kernel stacks for a non-first
thread in the process. Introduce separate kernel stack cache that keeps
some limited amount of preallocated kernel stacks to lower the latency
of thread allocation. Add vm_lowmem handler to prune the cache on
low memory condition. This way, system with reasonable amount of the
threads get lower latency of thread creation, while still not exhausting
significant portion of KVA for unused kstacks.

Submitted by:	peter [1]
Discussed with:	jhb, julian, peter
Reviewed by:	jhb
Tested by:	pho (and retested according to new test scenarious)
MFC after:	1 week
2009-09-01 11:41:51 +00:00

88 lines
3.9 KiB
C

/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*
* @(#)vm_extern.h 8.2 (Berkeley) 1/12/94
* $FreeBSD$
*/
#ifndef _VM_EXTERN_H_
#define _VM_EXTERN_H_
struct proc;
struct vmspace;
struct vnode;
#ifdef _KERNEL
int kernacc(void *, int, int);
vm_offset_t kmem_alloc(vm_map_t, vm_size_t);
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, vm_memattr_t memattr);
vm_offset_t kmem_alloc_nofault(vm_map_t, vm_size_t);
vm_offset_t kmem_alloc_wait(vm_map_t, vm_size_t);
void kmem_free(vm_map_t, vm_offset_t, vm_size_t);
void kmem_free_wakeup(vm_map_t, vm_offset_t, vm_size_t);
void kmem_init(vm_offset_t, vm_offset_t);
vm_offset_t kmem_malloc(vm_map_t, vm_size_t, boolean_t);
vm_map_t kmem_suballoc(vm_map_t, vm_offset_t *, vm_offset_t *, vm_size_t,
boolean_t);
void swapout_procs(int);
int useracc(void *, int, int);
int vm_fault(vm_map_t, vm_offset_t, vm_prot_t, int);
void vm_fault_copy_entry(vm_map_t, vm_map_t, vm_map_entry_t, vm_map_entry_t,
vm_ooffset_t *);
void vm_fault_unwire(vm_map_t, vm_offset_t, vm_offset_t, boolean_t);
int vm_fault_wire(vm_map_t, vm_offset_t, vm_offset_t, boolean_t, boolean_t);
int vm_forkproc(struct thread *, struct proc *, struct thread *, struct vmspace *, int);
void vm_waitproc(struct proc *);
int vm_mmap(vm_map_t, vm_offset_t *, vm_size_t, vm_prot_t, vm_prot_t, int, objtype_t, void *, vm_ooffset_t);
void vm_set_page_size(void);
struct vmspace *vmspace_alloc(vm_offset_t, vm_offset_t);
struct vmspace *vmspace_fork(struct vmspace *, vm_ooffset_t *);
int vmspace_exec(struct proc *, vm_offset_t, vm_offset_t);
int vmspace_unshare(struct proc *);
void vmspace_exit(struct thread *);
struct vmspace *vmspace_acquire_ref(struct proc *);
void vmspace_free(struct vmspace *);
void vmspace_exitfree(struct proc *);
void vnode_pager_setsize(struct vnode *, vm_ooffset_t);
int vslock(void *, size_t);
void vsunlock(void *, size_t);
void vm_object_print(/* db_expr_t */ long, boolean_t, /* db_expr_t */ long,
char *);
int vm_fault_quick(caddr_t v, int prot);
struct sf_buf *vm_imgact_map_page(vm_object_t object, vm_ooffset_t offset);
void vm_imgact_unmap_page(struct sf_buf *sf);
void vm_thread_dispose(struct thread *td);
int vm_thread_new(struct thread *td, int pages);
void vm_thread_swapin(struct thread *td);
void vm_thread_swapout(struct thread *td);
#endif /* _KERNEL */
#endif /* !_VM_EXTERN_H_ */