* [PATCH 4/10] I386 pgd clone under lock fix.patch
@ 2007-04-10 0:06 Zachary Amsden
2007-04-10 0:27 ` William Lee Irwin III
0 siblings, 1 reply; 2+ messages in thread
From: Zachary Amsden @ 2007-04-10 0:06 UTC (permalink / raw)
To: Andrew Morton, Andi Kleen, Jeremy Fitzhardinge, Rusty Russell,
Chris Wright, Virtualization Mailing List,
Linux Kernel Mailing List, Zachary Amsden
Cc: William Lee Irwin III
Copying of the pgd range must happen under the pgd_lock. This got broken by
the paravirt changes in the -mm tree. Badness can result if you copy the pgd
before being added to the list when splitting or rejoining large pages.
Signed-off-by: Zachary Amsden <zach@vmware.com>
diff -r 2247ff2c3fdb arch/i386/mm/pgtable.c
--- a/arch/i386/mm/pgtable.c Thu Apr 05 17:29:15 2007 -0700
+++ b/arch/i386/mm/pgtable.c Thu Apr 05 17:40:02 2007 -0700
@@ -241,18 +241,16 @@ void pgd_ctor(void *pgd, struct kmem_cac
/* !PAE, no pagetable sharing */
memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
+ spin_lock_irqsave(&pgd_lock, flags);
+
+ /* must happen under lock */
clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
swapper_pg_dir + USER_PTRS_PER_PGD,
KERNEL_PGD_PTRS);
-
- spin_lock_irqsave(&pgd_lock, flags);
-
- /* must happen under lock */
paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
__pa(swapper_pg_dir) >> PAGE_SHIFT,
USER_PTRS_PER_PGD,
KERNEL_PGD_PTRS);
-
pgd_list_add(pgd);
spin_unlock_irqrestore(&pgd_lock, flags);
}
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH 4/10] I386 pgd clone under lock fix.patch
2007-04-10 0:06 [PATCH 4/10] I386 pgd clone under lock fix.patch Zachary Amsden
@ 2007-04-10 0:27 ` William Lee Irwin III
0 siblings, 0 replies; 2+ messages in thread
From: William Lee Irwin III @ 2007-04-10 0:27 UTC (permalink / raw)
To: Zachary Amsden
Cc: Andrew Morton, Andi Kleen, Chris Wright,
Virtualization Mailing List, Linux Kernel Mailing List
On Mon, Apr 09, 2007 at 05:06:11PM -0700, Zachary Amsden wrote:
> Copying of the pgd range must happen under the pgd_lock. This got broken by
> the paravirt changes in the -mm tree. Badness can result if you copy the pgd
> before being added to the list when splitting or rejoining large pages.
> Signed-off-by: Zachary Amsden <zach@vmware.com>
Sorry my review missed this.
Acked-by: William Irwin <wli@holomorphy.com>
-- wli
^ permalink raw reply [flat|nested] 2+ messages in thread
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