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fix a lock order reversal during global boundary tag refill.

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thanks to chuq@
xxx: request pullup
This commit is contained in:
para 2013-01-04 08:28:38 +00:00
parent e17e68c7fd
commit 493b8304e5
1 changed files with 22 additions and 6 deletions
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28
sys/kern/subr_vmem.c
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@ -1,4 +1,4 @@
/* $NetBSD: subr_vmem.c,v 1.76 2012/09/13 21:44:50 joerg Exp $ */
/* $NetBSD: subr_vmem.c,v 1.77 2013/01/04 08:28:38 para Exp $ */
/*-
* Copyright (c)2006,2007,2008,2009 YAMAMOTO Takashi,
@ -34,7 +34,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_vmem.c,v 1.76 2012/09/13 21:44:50 joerg Exp $");
__KERNEL_RCSID(0, "$NetBSD: subr_vmem.c,v 1.77 2013/01/04 08:28:38 para Exp $");
#if defined(_KERNEL)
#include "opt_ddb.h"
@ -273,6 +273,7 @@ static int static_qc_pool_count = STATIC_QC_POOL_COUNT;
vmem_t *kmem_va_meta_arena;
vmem_t *kmem_meta_arena;
static kmutex_t vmem_refill_lock;
static kmutex_t vmem_btag_lock;
static LIST_HEAD(, vmem_btag) vmem_btag_freelist;
static size_t vmem_btag_freelist_count = 0;
@ -292,19 +293,26 @@ bt_refillglobal(vm_flag_t flags)
bt_t *bt;
int i;
mutex_enter(&vmem_refill_lock);
mutex_enter(&vmem_btag_lock);
if (vmem_btag_freelist_count > 0) {
mutex_exit(&vmem_btag_lock);
mutex_exit(&vmem_refill_lock);
return 0;
} else {
mutex_exit(&vmem_btag_lock);
}
if (vmem_alloc(kmem_meta_arena, PAGE_SIZE,
(flags & ~VM_FITMASK) | VM_INSTANTFIT | VM_POPULATING, &va) != 0) {
mutex_exit(&vmem_btag_lock);
mutex_exit(&vmem_refill_lock);
return ENOMEM;
}
VMEM_EVCNT_INCR(bt_pages);
mutex_enter(&vmem_btag_lock);
btp = (void *) va;
for (i = 0; i < (BT_PER_PAGE); i++) {
bt = btp;
@ -318,9 +326,14 @@ bt_refillglobal(vm_flag_t flags)
}
mutex_exit(&vmem_btag_lock);
bt_refill(kmem_arena, (flags & ~VM_FITMASK) | VM_INSTANTFIT);
bt_refill(kmem_va_meta_arena, (flags & ~VM_FITMASK) | VM_INSTANTFIT);
bt_refill(kmem_meta_arena, (flags & ~VM_FITMASK) | VM_INSTANTFIT);
bt_refill(kmem_arena, (flags & ~VM_FITMASK)
| VM_INSTANTFIT | VM_POPULATING);
bt_refill(kmem_va_meta_arena, (flags & ~VM_FITMASK)
| VM_INSTANTFIT | VM_POPULATING);
bt_refill(kmem_meta_arena, (flags & ~VM_FITMASK)
| VM_INSTANTFIT | VM_POPULATING);
mutex_exit(&vmem_refill_lock);
return 0;
}
@ -330,7 +343,9 @@ bt_refill(vmem_t *vm, vm_flag_t flags)
{
bt_t *bt;
bt_refillglobal(flags);
if (!(flags & VM_POPULATING)) {
bt_refillglobal(flags);
}
VMEM_LOCK(vm);
mutex_enter(&vmem_btag_lock);
@ -701,6 +716,7 @@ vmem_bootstrap(void)
{
mutex_init(&vmem_list_lock, MUTEX_DEFAULT, IPL_VM);
mutex_init(&vmem_refill_lock, MUTEX_DEFAULT, IPL_VM);
mutex_init(&vmem_btag_lock, MUTEX_DEFAULT, IPL_VM);
while (static_bt_count-- > 0) {