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Get rid of another lockmgr(9) consumer by using sx locks for the user

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maps.  We always acquire the sx lock exclusively here, but we can't
use a mutex because we want to be able to sleep while holding the
lock.  This is completely equivalent to what we were doing with the
lockmgr(9) locks before.

Approved by:	alc
This commit is contained in:
Maxime Henrion 2004-07-30 09:10:28 +00:00
parent fe6a04858c
commit 12c649749c
2 changed files with 19 additions and 27 deletions
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42
sys/vm/vm_map.c
View File

@ -197,7 +197,7 @@ vm_map_zfini(void *mem, int size)
map = (vm_map_t)mem;
mtx_destroy(&map->system_mtx);
lockdestroy(&map->lock);
sx_destroy(&map->lock);
}
static void
@ -210,7 +210,7 @@ vm_map_zinit(void *mem, int size)
map->size = 0;
map->infork = 0;
mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK);
lockinit(&map->lock, PVM, "thrd_sleep", 0, LK_NOPAUSE);
sx_init(&map->lock, "user map");
}
#ifdef INVARIANTS
@ -354,14 +354,11 @@ vmspace_exitfree(struct proc *p)
void
_vm_map_lock(vm_map_t map, const char *file, int line)
{
int error;
if (map->system_map)
_mtx_lock_flags(&map->system_mtx, 0, file, line);
else {
error = lockmgr(&map->lock, LK_EXCLUSIVE, NULL, curthread);
KASSERT(error == 0, ("%s: failed to get lock", __func__));
}
else
_sx_xlock(&map->lock, file, line);
map->timestamp++;
}
@ -372,20 +369,17 @@ _vm_map_unlock(vm_map_t map, const char *file, int line)
if (map->system_map)
_mtx_unlock_flags(&map->system_mtx, 0, file, line);
else
lockmgr(&map->lock, LK_RELEASE, NULL, curthread);
_sx_xunlock(&map->lock, file, line);
}
void
_vm_map_lock_read(vm_map_t map, const char *file, int line)
{
int error;
if (map->system_map)
_mtx_lock_flags(&map->system_mtx, 0, file, line);
else {
error = lockmgr(&map->lock, LK_EXCLUSIVE, NULL, curthread);
KASSERT(error == 0, ("%s: failed to get lock", __func__));
}
else
_sx_xlock(&map->lock, file, line);
}
void
@ -395,7 +389,7 @@ _vm_map_unlock_read(vm_map_t map, const char *file, int line)
if (map->system_map)
_mtx_unlock_flags(&map->system_mtx, 0, file, line);
else
lockmgr(&map->lock, LK_RELEASE, NULL, curthread);
_sx_xunlock(&map->lock, file, line);
}
int
@ -405,7 +399,7 @@ _vm_map_trylock(vm_map_t map, const char *file, int line)
error = map->system_map ?
!_mtx_trylock(&map->system_mtx, 0, file, line) :
lockmgr(&map->lock, LK_EXCLUSIVE | LK_NOWAIT, NULL, curthread);
!_sx_try_xlock(&map->lock, file, line);
if (error == 0)
map->timestamp++;
return (error == 0);
@ -418,7 +412,7 @@ _vm_map_trylock_read(vm_map_t map, const char *file, int line)
error = map->system_map ?
!_mtx_trylock(&map->system_mtx, 0, file, line) :
lockmgr(&map->lock, LK_EXCLUSIVE | LK_NOWAIT, NULL, curthread);
!_sx_try_xlock(&map->lock, file, line);
return (error == 0);
}
@ -426,13 +420,12 @@ int
_vm_map_lock_upgrade(vm_map_t map, const char *file, int line)
{
if (map->system_map) {
#ifdef INVARIANTS
if (map->system_map) {
_mtx_assert(&map->system_mtx, MA_OWNED, file, line);
#endif
} else
KASSERT(lockstatus(&map->lock, curthread) == LK_EXCLUSIVE,
("%s: lock not held", __func__));
_sx_assert(&map->lock, SX_XLOCKED, file, line);
#endif
map->timestamp++;
return (0);
}
@ -441,13 +434,12 @@ void
_vm_map_lock_downgrade(vm_map_t map, const char *file, int line)
{
if (map->system_map) {
#ifdef INVARIANTS
if (map->system_map) {
_mtx_assert(&map->system_mtx, MA_OWNED, file, line);
#endif
} else
KASSERT(lockstatus(&map->lock, curthread) == LK_EXCLUSIVE,
("%s: lock not held", __func__));
_sx_assert(&map->lock, SX_XLOCKED, file, line);
#endif
}
/*
@ -535,7 +527,7 @@ vm_map_init(vm_map_t map, vm_offset_t min, vm_offset_t max)
{
_vm_map_init(map, min, max);
mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK);
lockinit(&map->lock, PVM, "thrd_sleep", 0, LK_NOPAUSE);
sx_init(&map->lock, "user map");
}
/*

4
sys/vm/vm_map.h
View File

@ -67,7 +67,7 @@
#define _VM_MAP_
#include <sys/lock.h>
#include <sys/lockmgr.h>
#include <sys/sx.h>
#include <sys/_mutex.h>
/*
@ -164,7 +164,7 @@ vm_map_entry_behavior(vm_map_entry_t entry)
*/
struct vm_map {
struct vm_map_entry header; /* List of entries */
struct lock lock; /* Lock for map data */
struct sx lock; /* Lock for map data */
struct mtx system_mtx;
int nentries; /* Number of entries */
vm_size_t size; /* virtual size */