This is a note to let you know that I've just added the patch titled
mm: numa: do not clear PMD during PTE update scan
to the 3.12-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:
mm-numa-do-not-clear-pmd-during-pte-update-scan.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From [email protected] Tue Jan 7 09:49:21 2014
From: Mel Gorman <[email protected]>
Date: Tue, 7 Jan 2014 14:00:39 +0000
Subject: mm: numa: do not clear PMD during PTE update scan
To: [email protected]
Cc: [email protected], [email protected], [email protected], Mel Gorman
<[email protected]>, [email protected]
Message-ID: <[email protected]>
From: Mel Gorman <[email protected]>
commit 5a6dac3ec5f583cc8ee7bc53b5500a207c4ca433 upstream.
If the PMD is flushed then a parallel fault in handle_mm_fault() will
enter the pmd_none and do_huge_pmd_anonymous_page() path where it'll
attempt to insert a huge zero page. This is wasteful so the patch
avoids clearing the PMD when setting pmd_numa.
Signed-off-by: Mel Gorman <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Cc: Alex Thorlton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
mm/huge_memory.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1474,20 +1474,22 @@ int change_huge_pmd(struct vm_area_struc
if (__pmd_trans_huge_lock(pmd, vma) == 1) {
pmd_t entry;
- entry = pmdp_get_and_clear(mm, addr, pmd);
if (!prot_numa) {
+ entry = pmdp_get_and_clear(mm, addr, pmd);
entry = pmd_modify(entry, newprot);
BUG_ON(pmd_write(entry));
+ set_pmd_at(mm, addr, pmd, entry);
} else {
struct page *page = pmd_page(*pmd);
+ entry = *pmd;
/* only check non-shared pages */
if (page_mapcount(page) == 1 &&
!pmd_numa(*pmd)) {
entry = pmd_mknuma(entry);
+ set_pmd_at(mm, addr, pmd, entry);
}
}
- set_pmd_at(mm, addr, pmd, entry);
spin_unlock(&vma->vm_mm->page_table_lock);
ret = 1;
}
Patches currently in stable-queue which might be from [email protected] are
queue-3.12/sched-numa-skip-inaccessible-vmas.patch
queue-3.12/mm-compaction-respect-ignore_skip_hint-in-update_pageblock_skip.patch
queue-3.12/mm-clear-pmd_numa-before-invalidating.patch
queue-3.12/mm-numa-ensure-anon_vma-is-locked-to-prevent-parallel-thp-splits.patch
queue-3.12/mm-numa-do-not-clear-pte-for-pte_numa-update.patch
queue-3.12/mm-hugetlb-check-for-pte-null-pointer-in-__page_check_address.patch
queue-3.12/mm-numa-serialise-parallel-get_user_page-against-thp-migration.patch
queue-3.12/mm-munlock-fix-deadlock-in-__munlock_pagevec.patch
queue-3.12/mm-numa-avoid-unnecessary-work-on-the-failure-path.patch
queue-3.12/mm-page_alloc-revert-numa-aspect-of-fair-allocation-policy.patch
queue-3.12/mm-mempolicy-correct-putback-method-for-isolate-pages-if-failed.patch
queue-3.12/mm-numa-do-not-clear-pmd-during-pte-update-scan.patch
queue-3.12/mm-numa-call-mmu-notifiers-on-thp-migration.patch
queue-3.12/mm-munlock-fix-a-bug-where-thp-tail-page-is-encountered.patch
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