[src/netbsd-6-0]: src/sys/kern Pull up following revision(s) (requested by pa...

[riz <riz%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b504d77c93e1
branches:  netbsd-6-0
changeset: 774752:b504d77c93e1
user:      riz <riz%NetBSD.org@localhost>
date:      Fri Feb 08 20:22:18 2013 +0000

description:
Pull up following revision(s) (requested by para in ticket #789):
        sys/kern/subr_vmem.c: revision 1.81
        sys/kern/subr_vmem.c: revision 1.77
fix a lock order reversal during global boundary tag refill.
thanks to chuq@
xxx: request pullup
Fix release of vmem_btag_lock (don't release twice in error path)

diffstat:

 sys/kern/subr_vmem.c |  28 +++++++++++++++++++++-------
 1 files changed, 21 insertions(+), 7 deletions(-)

diffs (89 lines):

diff -r fe25923b9cfd -r b504d77c93e1 sys/kern/subr_vmem.c
--- a/sys/kern/subr_vmem.c      Fri Feb 08 19:55:24 2013 +0000
+++ b/sys/kern/subr_vmem.c      Fri Feb 08 20:22:18 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_vmem.c,v 1.72.2.1 2012/04/03 16:14:02 riz Exp $   */
+/*     $NetBSD: subr_vmem.c,v 1.72.2.1.4.1 2013/02/08 20:22:18 riz 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 1.72.2.1 2012/04/03 16:14:02 riz Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_vmem.c,v 1.72.2.1.4.1 2013/02/08 20:22:18 riz Exp $");
 
 #if defined(_KERNEL)
 #include "opt_ddb.h"
@@ -263,6 +263,7 @@
 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;
@@ -282,19 +283,24 @@
        bt_t *bt;
        int i;
 
+       mutex_enter(&vmem_refill_lock);
+
        mutex_enter(&vmem_btag_lock);
        if (vmem_btag_freelist_count > (BT_MINRESERVE * 16)) {
                mutex_exit(&vmem_btag_lock);
+               mutex_exit(&vmem_refill_lock);
                return 0;
        }
+       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;
@@ -308,9 +314,14 @@
        }
        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;
 }
@@ -320,7 +331,9 @@
 {
        bt_t *bt;
 
-       bt_refillglobal(flags);
+       if (!(flags & VM_POPULATING)) {
+               bt_refillglobal(flags);
+       }
 
        VMEM_LOCK(vm);
        mutex_enter(&vmem_btag_lock);
@@ -691,6 +704,7 @@
 {
 
        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) {