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authorMiaohe Lin <linmiaohe@huawei.com>2021-02-24 12:06:57 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-24 13:38:32 -0800
commit0aa7f3544aaa02a7df5095dc1bc338bcd73b7872 (patch)
treefb419d52f2e9880dd12b4a009a7eaa0815bfe699
parenta1ba9da8f0f9a37d900ff7eff66482cf7de8015e (diff)
downloadlinux-0aa7f3544aaa02a7df5095dc1bc338bcd73b7872.tar.bz2
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@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/hugetlb.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 66edef56a070..0173f9f2fcc6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3591,6 +3591,9 @@ static int hugetlb_acct_memory(struct hstate *h, long delta)
{
int ret = -ENOMEM;
+ if (!delta)
+ return 0;
+
spin_lock(&hugetlb_lock);
/*
* When cpuset is configured, it breaks the strict hugetlb page