The patch titled
mm: thp: optimize memcg charge in khugepaged
has been added to the -mm tree. Its filename is
mm-thp-optimize-memcg-charge-in-khugepaged.patch
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------------------------------------------------------
Subject: mm: thp: optimize memcg charge in khugepaged
From: Andrea Arcangeli <aarcange@xxxxxxxxxx>
We don't need to hold the mmmap_sem through mem_cgroup_newpage_charge(),
the mmap_sem is only hold for keeping the vma stable and we don't need the
vma stable anymore after we return from alloc_hugepage_vma().
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Johannes Weiner <jweiner@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff -puN mm/huge_memory.c~mm-thp-optimize-memcg-charge-in-khugepaged mm/huge_memory.c
--- a/mm/huge_memory.c~mm-thp-optimize-memcg-charge-in-khugepaged
+++ a/mm/huge_memory.c
@@ -1771,12 +1771,9 @@ static void collapse_huge_page(struct mm
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
#ifndef CONFIG_NUMA
+ up_read(&mm->mmap_sem);
VM_BUG_ON(!*hpage);
new_page = *hpage;
- if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
- up_read(&mm->mmap_sem);
- return;
- }
#else
VM_BUG_ON(*hpage);
/*
@@ -1791,22 +1788,22 @@ static void collapse_huge_page(struct mm
*/
new_page = alloc_hugepage_vma(khugepaged_defrag(), vma, address,
node, __GFP_OTHER_NODE);
+ /* after allocating the hugepage upgrade to mmap_sem write mode */
+ up_read(&mm->mmap_sem);
if (unlikely(!new_page)) {
- up_read(&mm->mmap_sem);
count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
*hpage = ERR_PTR(-ENOMEM);
return;
}
+#endif
+
count_vm_event(THP_COLLAPSE_ALLOC);
if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
- up_read(&mm->mmap_sem);
+#ifdef CONFIG_NUMA
put_page(new_page);
+#endif
return;
}
-#endif
-
- /* after allocating the hugepage upgrade to mmap_sem write mode */
- up_read(&mm->mmap_sem);
/*
* Prevent all access to pagetables with the exception of
_
Patches currently in -mm which might be from aarcange@xxxxxxxxxx are
mm-check-if-pte-is-already-allocated-during-page-fault.patch
mm-thp-fix-dev-zero-map_private-and-vm_flags-cleanups.patch
mm-compaction-reverse-the-change-that-forbade-sync-migraton-with-__gfp_no_kswapd.patch
mm-thp-optimize-memcg-charge-in-khugepaged.patch
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