lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 23 Jun 2017 15:24:36 +0200 From: Michal Hocko <mhocko@...nel.org> To: David Rientjes <rientjes@...gle.com> Cc: Andrew Morton <akpm@...ux-foundation.org>, Larry Finger <Larry.Finger@...inger.net>, Vlastimil Babka <vbabka@...e.cz>, LKML <linux-kernel@...r.kernel.org>, linux-mm@...ck.org Subject: Re: [patch for-4.12] mm, thp: remove cond_resched from __collapse_huge_page_copy On Mon 19-06-17 13:43:11, David Rientjes wrote: > 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. > > Reported-by: Larry Finger <Larry.Finger@...inger.net> > Signed-off-by: David Rientjes <rientjes@...gle.com> Acked-by: Michal Hocko <mhocko@...e.com> > --- > Note: Larry should be back as of June 17 to test if this fixes the > reported issue. > > mm/khugepaged.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > --- 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(); > } > } > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@...ck.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@...ck.org"> email@...ck.org </a> -- Michal Hocko SUSE Labs
Powered by blists - more mailing lists