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authorDavid Rientjes <rientjes@google.com>2017-06-23 15:08:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-06-23 16:15:55 -0700
commitc891d9f6bf2a78c9c657656872a60807820db4c8 (patch)
treece2dac47780133fee1e18579af6070add62319b5
parenta38371cba67539ce6a5d5324db34bc2ddaf66cc1 (diff)
downloadlinux-c891d9f6bf2a78c9c657656872a60807820db4c8.tar.bz2
mm, thp: remove cond_resched from __collapse_huge_page_copy
This is a partial revert of commit 338a16ba1549 ("mm, thp: copying user pages must schedule on collapse") which added a cond_resched() to __collapse_huge_page_copy(). On x86 with CONFIG_HIGHPTE, __collapse_huge_page_copy is called in atomic context and thus scheduling is not possible. This is only a possible config on arm and i386. Although need_resched has been shown to be set for over 100 jiffies while doing the iteration in __collapse_huge_page_copy, this is better than doing if (in_atomic()) cond_resched() to cover only non-CONFIG_HIGHPTE configs. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1706191341550.97821@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Larry Finger <Larry.Finger@lwfinger.net> Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/khugepaged.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 945fd1ca49b5..df4ebdb2b10a 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -652,7 +652,6 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page,
spin_unlock(ptl);
free_page_and_swap_cache(src_page);
}
- cond_resched();
}
}