From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934487AbeDXNlz (ORCPT ); Tue, 24 Apr 2018 09:41:55 -0400 Received: from foss.arm.com ([217.140.101.70]:53528 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933173AbeDXNlw (ORCPT ); Tue, 24 Apr 2018 09:41:52 -0400 Date: Tue, 24 Apr 2018 14:41:48 +0100 From: Catalin Marinas To: Michal Hocko Cc: Chunyu Hu , Dmitry Vyukov , Chunyu Hu , LKML , Linux-MM Subject: Re: [RFC] mm: kmemleak: replace __GFP_NOFAIL to GFP_NOWAIT in gfp_kmemleak_mask Message-ID: <20180424134148.qkvqqa4c37l6irvg@armageddon.cambridge.arm.com> References: <1524243513-29118-1-git-send-email-chuhu@redhat.com> <20180420175023.3c4okuayrcul2bom@armageddon.cambridge.arm.com> <20180422125141.GF17484@dhcp22.suse.cz> <20180424132057.GE17484@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180424132057.GE17484@dhcp22.suse.cz> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 24, 2018 at 07:20:57AM -0600, Michal Hocko wrote: > On Mon 23-04-18 12:17:32, Chunyu Hu wrote: > [...] > > So if there is a new flag, it would be the 25th bits. > > No new flags please. Can you simply store a simple bool into fail_page_alloc > and have save/restore api for that? For kmemleak, we probably first hit failslab. Something like below may do the trick: diff --git a/mm/failslab.c b/mm/failslab.c index 1f2f248e3601..63f13da5cb47 100644 --- a/mm/failslab.c +++ b/mm/failslab.c @@ -29,6 +29,9 @@ bool __should_failslab(struct kmem_cache *s, gfp_t gfpflags) if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB)) return false; + if (s->flags & SLAB_NOLEAKTRACE) + return false; + return should_fail(&failslab.attr, s->object_size); } Can we get a second should_fail() via should_fail_alloc_page() if a new slab page is allocated? -- Catalin