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- Increment the vm_map's timestamp if _vm_map_trylock() succeeds.

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- Introduce map_sleep_mtx and use it to replace Giant in
   vm_map_unlock_and_wait() and vm_map_wakeup().  (Original
   version by: tegge.)
This commit is contained in:
Alan Cox 2002-12-30 00:41:33 +00:00
parent 2ae92e3e07
commit 3a92e5d5e9
1 changed files with 11 additions and 10 deletions
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21
sys/vm/vm_map.c
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@ -133,6 +133,7 @@
* maps and requires map entries.
*/
static struct mtx map_sleep_mtx;
static uma_zone_t mapentzone;
static uma_zone_t kmapentzone;
static uma_zone_t mapzone;
@ -152,6 +153,7 @@ static void vmspace_zdtor(void *mem, int size, void *arg);
void
vm_map_startup(void)
{
mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF);
mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL,
#ifdef INVARIANTS
vm_map_zdtor,
@ -412,6 +414,8 @@ _vm_map_trylock(vm_map_t map, const char *file, int line)
if (map->system_map)
GIANT_REQUIRED;
error = lockmgr(&map->lock, LK_EXCLUSIVE | LK_NOWAIT, NULL, curthread);
if (error == 0)
map->timestamp++;
return (error == 0);
}
@ -439,13 +443,10 @@ _vm_map_lock_downgrade(vm_map_t map, const char *file, int line)
int
vm_map_unlock_and_wait(vm_map_t map, boolean_t user_wait)
{
int retval;
mtx_lock(&Giant);
mtx_lock(&map_sleep_mtx);
vm_map_unlock(map);
retval = tsleep(&map->root, PVM, "vmmapw", 0);
mtx_unlock(&Giant);
return (retval);
return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps", 0));
}
/*
@ -456,12 +457,12 @@ vm_map_wakeup(vm_map_t map)
{
/*
* Acquire and release Giant to prevent a wakeup() from being
* performed (and lost) between the vm_map_unlock() and the
* tsleep() in vm_map_unlock_and_wait().
* Acquire and release map_sleep_mtx to prevent a wakeup()
* from being performed (and lost) between the vm_map_unlock()
* and the msleep() in vm_map_unlock_and_wait().
*/
mtx_lock(&Giant);
mtx_unlock(&Giant);
mtx_lock(&map_sleep_mtx);
mtx_unlock(&map_sleep_mtx);
wakeup(&map->root);
}