From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F133C00A89 for ; Thu, 5 Nov 2020 13:20:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AE09F206FA for ; Thu, 5 Nov 2020 13:20:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="khs1VFwA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE09F206FA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CF2056B0110; Thu, 5 Nov 2020 08:20:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CA2D36B0112; Thu, 5 Nov 2020 08:20:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B92586B0113; Thu, 5 Nov 2020 08:20:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0063.hostedemail.com [216.40.44.63]) by kanga.kvack.org (Postfix) with ESMTP id 894EB6B0110 for ; Thu, 5 Nov 2020 08:20:00 -0500 (EST) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 28223181AEF00 for ; Thu, 5 Nov 2020 13:20:00 +0000 (UTC) X-FDA: 77450422560.24.bite06_5809db7272ca Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin24.hostedemail.com (Postfix) with ESMTP id 053171A4A5 for ; Thu, 5 Nov 2020 13:19:59 +0000 (UTC) X-HE-Tag: bite06_5809db7272ca X-Filterd-Recvd-Size: 5816 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Thu, 5 Nov 2020 13:19:59 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1604582398; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+HvDrbMYFGh2s7Sy38sP4VkLMgxkOofo0TUquyQWwZY=; b=khs1VFwAQF2sfQUKnKH22BI5jya9pkZWhNsCjkLgrMg9EJktbgTFU4zFmlostMnJ4n7Z6T 4veK7DdyzRh3sNCniQszE2ZPp64ZPoanXfisZ8/Rm8ApclFzWhDtw1eBca0WN5HgSGOqKU tilizJ1hbrn/801k0L5I8R3IqT1xncI= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 49634AD21; Thu, 5 Nov 2020 13:19:58 +0000 (UTC) Date: Thu, 5 Nov 2020 14:19:57 +0100 From: Michal Hocko To: Vlastimil Babka Cc: Feng Tang , Andrew Morton , Johannes Weiner , Matthew Wilcox , Mel Gorman , dave.hansen@intel.com, ying.huang@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 0/2] mm: fix OOMs for binding workloads to movable zone only node Message-ID: <20201105131957.GI21348@dhcp22.suse.cz> References: <20201104071308.GN21990@dhcp22.suse.cz> <20201104073826.GA15700@shbuild999.sh.intel.com> <20201104075819.GA10052@dhcp22.suse.cz> <20201104084021.GB15700@shbuild999.sh.intel.com> <20201104085343.GA18718@dhcp22.suse.cz> <20201105014028.GA86777@shbuild999.sh.intel.com> <20201105120818.GC21348@dhcp22.suse.cz> <4029c079-b1f3-f290-26b6-a819c52f5200@suse.cz> <20201105125828.GG21348@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu 05-11-20 14:14:25, Vlastimil Babka wrote: > On 11/5/20 1:58 PM, Michal Hocko wrote: > > On Thu 05-11-20 13:53:24, Vlastimil Babka wrote: > > > On 11/5/20 1:08 PM, Michal Hocko wrote: > > > > On Thu 05-11-20 09:40:28, Feng Tang wrote: > > > > > > > Could you be more specific? This sounds like a bug. Allocations > > > > > > shouldn't spill over to a node which is not in the cpuset. There are few > > > > > > exceptions like IRQ context but that shouldn't happen regurarly. > > > > > > > I mean when the docker starts, it will spawn many processes > > > which obey > > > > > the mem binding set, and they have some kernel page requests, which got > > > > > successfully allocated, like the following callstack: > > > > > > > [ 567.044953] CPU: 1 PID: 2021 Comm: runc:[1:CHILD] > > > Tainted: G W I 5.9.0-rc8+ #6 > > > > > [ 567.044956] Hardware name: /NUC6i5SYB, BIOS SYSKLi35.86A.0051.2016.0804.1114 08/04/2016 > > > > > [ 567.044958] Call Trace: > > > > > [ 567.044972] dump_stack+0x74/0x9a > > > > > [ 567.044978] __alloc_pages_nodemask.cold+0x22/0xe5 > > > > > [ 567.044986] alloc_pages_current+0x87/0xe0 > > > > > [ 567.044991] allocate_slab+0x2e5/0x4f0 > > > > > [ 567.044996] ___slab_alloc+0x380/0x5d0 > > > > > [ 567.045021] __slab_alloc+0x20/0x40 > > > > > [ 567.045025] kmem_cache_alloc+0x2a0/0x2e0 > > > > > [ 567.045033] mqueue_alloc_inode+0x1a/0x30 > > > > > [ 567.045041] alloc_inode+0x22/0xa0 > > > > > [ 567.045045] new_inode_pseudo+0x12/0x60 > > > > > [ 567.045049] new_inode+0x17/0x30 > > > > > [ 567.045052] mqueue_get_inode+0x45/0x3b0 > > > > > [ 567.045060] mqueue_fill_super+0x41/0x70 > > > > > [ 567.045067] vfs_get_super+0x7f/0x100 > > > > > [ 567.045074] get_tree_keyed+0x1d/0x20 > > > > > [ 567.045080] mqueue_get_tree+0x1c/0x20 > > > > > [ 567.045086] vfs_get_tree+0x2a/0xc0 > > > > > [ 567.045092] fc_mount+0x13/0x50 > > > > > [ 567.045099] mq_create_mount+0x92/0xe0 > > > > > [ 567.045102] mq_init_ns+0x3b/0x50 > > > > > [ 567.045106] copy_ipcs+0x10a/0x1b0 > > > > > [ 567.045113] create_new_namespaces+0xa6/0x2b0 > > > > > [ 567.045118] unshare_nsproxy_namespaces+0x5a/0xb0 > > > > > [ 567.045124] ksys_unshare+0x19f/0x360 > > > > > [ 567.045129] __x64_sys_unshare+0x12/0x20 > > > > > [ 567.045135] do_syscall_64+0x38/0x90 > > > > > [ 567.045143] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > > > > For it, the __alloc_pages_nodemask() will first try > > > process's targed > > > > > nodemask(unmovable node here), and there is no availabe zone, so it > > > > > goes with the NULL nodemask, and get a page in the slowpath. > > > > > OK, I see your point now. I was not aware of the slab allocator > > > not > > > > following cpusets. Sounds like a bug to me. > > > > > > SLAB and SLUB seem to not care about cpusets in the fast path. > > > > Is a fallback to a different node which is outside of the cpuset > > possible? > > AFAICS anything in per-cpu cache will be allocated without looking at the > cpuset, so it can be outside of the cpuset. In SLUB slowpath, > get_partial_node() looking for fallback on the same node will also not look > at cpuset. get_any_partial() looking for a fallback allocation on any node > does check cpuset_zone_allowed() and obey it strictly. A fallback to page > allocator will obey whatever page allocator obeys. IIUC this means that if there is no strong CPU binding to cpuset nodes then a runaway is possible. Albeit only partially and relying on somebody to fill up pcp object caches, right? Is that an overlook or a decision design or a performance optimization? -- Michal Hocko SUSE Labs