Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752166AbdFZMNz (ORCPT ); Mon, 26 Jun 2017 08:13:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:33315 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752132AbdFZMNr (ORCPT ); Mon, 26 Jun 2017 08:13:47 -0400 Subject: Re: [PATCH 6/6] mm, migration: do not trigger OOM killer when migrating memory To: Michal Hocko , Andrew Morton Cc: Johannes Weiner , Mel Gorman , NeilBrown , LKML , linux-mm@kvack.org, Michal Hocko References: <20170623085345.11304-1-mhocko@kernel.org> <20170623085345.11304-7-mhocko@kernel.org> From: Vlastimil Babka Message-ID: <35aecfe6-4ef0-5d7f-cda0-fbe68cf356dc@suse.cz> Date: Mon, 26 Jun 2017 14:13:44 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <20170623085345.11304-7-mhocko@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2523 Lines: 67 On 06/23/2017 10:53 AM, Michal Hocko wrote: > From: Michal Hocko > > Page migration (for memory hotplug, soft_offline_page or mbind) needs > to allocate a new memory. This can trigger an oom killer if the target > memory is depleated. Although quite unlikely, still possible, especially > for the memory hotplug (offlining of memoery). Up to now we didn't > really have reasonable means to back off. __GFP_NORETRY can fail just > too easily and __GFP_THISNODE sticks to a single node and that is not > suitable for all callers. > > But now that we have __GFP_RETRY_MAYFAIL we should use it. It is > preferable to fail the migration than disrupt the system by killing some > processes. > > Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka > --- > include/linux/migrate.h | 2 +- > mm/memory-failure.c | 3 ++- > mm/mempolicy.c | 3 ++- > 3 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/include/linux/migrate.h b/include/linux/migrate.h > index f80c9882403a..9f5885dae80e 100644 > --- a/include/linux/migrate.h > +++ b/include/linux/migrate.h > @@ -34,7 +34,7 @@ extern char *migrate_reason_names[MR_TYPES]; > static inline struct page *new_page_nodemask(struct page *page, int preferred_nid, > nodemask_t *nodemask) > { > - gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE; > + gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL; > > if (PageHuge(page)) > return alloc_huge_page_nodemask(page_hstate(compound_head(page)), > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index e2e0cb0e1d0f..fe0c484c6fdb 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1492,7 +1492,8 @@ static struct page *new_page(struct page *p, unsigned long private, int **x) > > return alloc_huge_page_node(hstate, nid); > } else { > - return __alloc_pages_node(nid, GFP_HIGHUSER_MOVABLE, 0); > + return __alloc_pages_node(nid, > + GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL, 0); > } > } > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index 7d8e56214ac0..d911fa5cb2a7 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -1078,7 +1078,8 @@ static struct page *new_page(struct page *page, unsigned long start, int **x) > /* > * if !vma, alloc_page_vma() will use task or system default policy > */ > - return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); > + return alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL, > + vma, address); > } > #else > >