The patch titled
Subject: mm/hugetlb: avoid unnecessary hugetlb_acct_memory() call
has been added to the -mm tree. Its filename is
mm-hugetlb-avoid-unnecessary-hugetlb_acct_memory-call.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-hugetlb-avoid-unnecessary-hugetlb_acct_memory-call.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-hugetlb-avoid-unnecessary-hugetlb_acct_memory-call.patch
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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: mm/hugetlb: avoid unnecessary hugetlb_acct_memory() call
When reservation accounting remains unchanged, hugetlb_acct_memory() will
do nothing except holding and releasing hugetlb_lock. We should avoid
this unnecessary hugetlb_lock lock/unlock cycle which is happening on
'most' hugetlb munmap operations by check delta against 0 at the beginning
of hugetlb_acct_memory.
Link: https://lkml.kernel.org/r/20210115092013.61012-1-linmiaohe@xxxxxxxxxx
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 3 +++
1 file changed, 3 insertions(+)
--- a/mm/hugetlb.c~mm-hugetlb-avoid-unnecessary-hugetlb_acct_memory-call
+++ a/mm/hugetlb.c
@@ -3588,6 +3588,9 @@ static int hugetlb_acct_memory(struct hs
{
int ret = -ENOMEM;
+ if (!delta)
+ return 0;
+
spin_lock(&hugetlb_lock);
/*
* When cpuset is configured, it breaks the strict hugetlb page
_
Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are
mm-hugetlb-fix-potential-double-free-in-hugetlb_register_node-error-path.patch
mm-hugetlb-avoid-unnecessary-hugetlb_acct_memory-call.patch
mm-compaction-remove-duplicated-vm_bug_on_page-pagelocked.patch
