This is a note to let you know that I've just added the patch titled
x86, mm, hugetlb: Add missing TLB page invalidation for hugetlb_cow()
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-mm-hugetlb-add-missing-tlb-page-invalidation-for-hugetlb_cow.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 9844f5462392b53824e8b86726e7c33b5ecbb676 Mon Sep 17 00:00:00 2001
From: Anthony Iliopoulos <[email protected]>
Date: Wed, 14 May 2014 11:29:48 +0200
Subject: x86, mm, hugetlb: Add missing TLB page invalidation for hugetlb_cow()
From: Anthony Iliopoulos <[email protected]>
commit 9844f5462392b53824e8b86726e7c33b5ecbb676 upstream.
The invalidation is required in order to maintain proper semantics
under CoW conditions. In scenarios where a process clones several
threads, a thread operating on a core whose DTLB entry for a
particular hugepage has not been invalidated, will be reading from
the hugepage that belongs to the forked child process, even after
hugetlb_cow().
The thread will not see the updated page as long as the stale DTLB
entry remains cached, the thread attempts to write into the page,
the child process exits, or the thread gets migrated to a different
processor.
Signed-off-by: Anthony Iliopoulos <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Suggested-by: Shay Goikhman <[email protected]>
Acked-by: Dave Hansen <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/x86/include/asm/hugetlb.h | 1 +
1 file changed, 1 insertion(+)
--- a/arch/x86/include/asm/hugetlb.h
+++ b/arch/x86/include/asm/hugetlb.h
@@ -51,6 +51,7 @@ static inline pte_t huge_ptep_get_and_cl
static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep)
{
+ ptep_clear_flush(vma, addr, ptep);
}
static inline int huge_pte_none(pte_t pte)
Patches currently in stable-queue which might be from
[email protected] are
queue-3.4/x86-mm-hugetlb-add-missing-tlb-page-invalidation-for-hugetlb_cow.patch
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