Subject: + hugetlb-properly-account-rss.patch added to -mm tree
To: joern@xxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Fri, 28 Jun 2013 15:03:29 -0700
The patch titled
Subject: hugetlb: properly account rss
has been added to the -mm tree. Its filename is
hugetlb-properly-account-rss.patch
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From: Joern Engel <joern@xxxxxxxxx>
Subject: hugetlb: properly account rss
When moving a program from mmap'ing small pages to mmap'ing huge pages, a
remarkable drop in rss ensues. For some reason hugepages were never
accounted for in rss, which in my book is a clear bug. Sadly this bug has
been present in hugetlbfs since it was merged back in 2002. There is
every chance existing programs depend on hugepages not being counted as
rss.
I think the correct solution is to fix the bug and wait for someone to
complain. It is just as likely that noone cares - as evidenced by the
fact that noone seems to have noticed for ten years.
Signed-off-by: Joern Engel <joern@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 4 ++++
1 file changed, 4 insertions(+)
diff -puN mm/hugetlb.c~hugetlb-properly-account-rss mm/hugetlb.c
--- a/mm/hugetlb.c~hugetlb-properly-account-rss
+++ a/mm/hugetlb.c
@@ -1191,6 +1191,7 @@ static struct page *alloc_huge_page(stru
set_page_private(page, (unsigned long)spool);
vma_commit_reservation(h, vma, addr);
+ add_mm_counter(vma->vm_mm, MM_ANONPAGES, pages_per_huge_page(h));
return page;
}
@@ -2439,6 +2440,9 @@ again:
if (huge_pte_dirty(pte))
set_page_dirty(page);
+ /* -pages_per_huge_page(h) wouldn't get sign-extended */
+ add_mm_counter(vma->vm_mm, MM_ANONPAGES, -1 << h->order);
+
page_remove_rmap(page);
force_flush = !__tlb_remove_page(tlb, page);
if (force_flush)
_
Patches currently in -mm which might be from joern@xxxxxxxxx are
linux-next.patch
hugetlb-properly-account-rss.patch
mmap-allow-map_hugetlb-for-hugetlbfs-files-v2.patch
nilfs2-implement-calculation-of-free-inodes-count.patch
nilfs2-use-atomic64_t-type-for-inodes_count-and-blocks_count-fields-in-nilfs_root-struct.patch
selftests-exit-1-on-failure.patch
self-test-fix-make-clean.patch
selftests-add-hugetlbfstest.patch
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