From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id B9B6D6B0292 for ; Fri, 23 Jun 2017 16:43:09 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id v88so15695635wrb.1 for ; Fri, 23 Jun 2017 13:43:09 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id t70si4916421wme.143.2017.06.23.13.43.07 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 23 Jun 2017 13:43:08 -0700 (PDT) Date: Fri, 23 Jun 2017 13:43:05 -0700 From: Andrew Morton Subject: Re: [PATCH 6/6] mm, migration: do not trigger OOM killer when migrating memory Message-Id: <20170623134305.4f59f673051120f95303fd89@linux-foundation.org> In-Reply-To: <20170623085345.11304-7-mhocko@kernel.org> References: <20170623085345.11304-1-mhocko@kernel.org> <20170623085345.11304-7-mhocko@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Vlastimil Babka , Johannes Weiner , Mel Gorman , NeilBrown , LKML , linux-mm@kvack.org, Michal Hocko On Fri, 23 Jun 2017 10:53:45 +0200 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. I'm not sure which tree this is against... > --- 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); > } > } new_page() is now static struct page *new_page(struct page *p, unsigned long private, int **x) { int nid = page_to_nid(p); return new_page_nodemask(p, nid, &node_states[N_MEMORY]); } and new_page_nodemask() uses __GFP_RETRY_MAYFAIL so I simply dropped the above hunk. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org