From patchwork Fri Jan 28 19:56:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 12729013 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B05EC433F5 for ; Fri, 28 Jan 2022 19:57:32 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B59056B0102; Fri, 28 Jan 2022 14:57:31 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A8E8C6B0106; Fri, 28 Jan 2022 14:57:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 908E76B0108; Fri, 28 Jan 2022 14:57:31 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0001.hostedemail.com [216.40.44.1]) by kanga.kvack.org (Postfix) with ESMTP id 8016A6B0102 for ; Fri, 28 Jan 2022 14:57:31 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 3E82518209A93 for ; Fri, 28 Jan 2022 19:57:31 +0000 (UTC) X-FDA: 79080755502.09.501CA96 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf19.hostedemail.com (Postfix) with ESMTP id CE0F71A0003 for ; Fri, 28 Jan 2022 19:57:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643399850; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=4AGco3DPR26g1wodgd1tvssEUzEAzvT6zrwEdwptTuI=; b=ESUZ0zB243TwUYieRoCByb3GpzpzuCz35EPbJeI5h/jEmKbMXiKpRK0wlLi7iFEmMEdFjy d2oC3/hsW7XBHjjRWF9WO18lTh6oq7MjkA7UaFTc8OvtSE6+75FSG4hLlXQl+k99J1X82w elQlcneuAFOY1cpNebduQp3ErQQbzh4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-446-fDMU9u6qPrK01Ep4O1Qnuw-1; Fri, 28 Jan 2022 14:57:24 -0500 X-MC-Unique: fDMU9u6qPrK01Ep4O1Qnuw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 818EF1083F64; Fri, 28 Jan 2022 19:57:23 +0000 (UTC) Received: from llong.com (unknown [10.22.33.1]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8D5925DB82; Fri, 28 Jan 2022 19:57:10 +0000 (UTC) From: Waiman Long To: Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, Rafael Aquini , Waiman Long Subject: [PATCH 0/2] mm/page_owner: Extend page_owner to show memcg Date: Fri, 28 Jan 2022 14:56:40 -0500 Message-Id: <20220128195642.416743-1-longman@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Rspam-User: nil X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: CE0F71A0003 X-Stat-Signature: e59a3qcbbdwcwbkpwpcqo8uzzxw18qwm Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ESUZ0zB2; spf=none (imf19.hostedemail.com: domain of longman@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=longman@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-HE-Tag: 1643399850-781470 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000082, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: While debugging the constant increase in percpu memory consumption on a system that spawned large number of containers, it was found that a lot of offlined mem_cgroup structures remained in place without being freed. Further investigation indicated that those mem_cgroup structures were pinned by some pages. In order to find out what those pages are, the existing page_owner debugging tool is extended to show memory cgroup information and whether those memcgs are offlined or not. With the enhanced page_owner tool, the following is a typical page that pinned the mem_cgroup structure in my test case: Page allocated via order 0, mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 62760, ts 119274296592 ns, free_ts 118989764823 ns PFN 1273412 type Movable Block 2487 type Movable Flags 0x17ffffc00c001c(uptodate|dirty|lru|reclaim|swapbacked|node=0|zone=2|lastcpupid=0x1fffff) prep_new_page+0x8e/0xb0 get_page_from_freelist+0xc4d/0xe50 __alloc_pages+0x172/0x320 alloc_pages_vma+0x84/0x230 shmem_alloc_page+0x3f/0x90 shmem_alloc_and_acct_page+0x76/0x1c0 shmem_getpage_gfp+0x48d/0x890 shmem_write_begin+0x36/0xc0 generic_perform_write+0xed/0x1d0 __generic_file_write_iter+0xdc/0x1b0 generic_file_write_iter+0x5d/0xb0 new_sync_write+0x11f/0x1b0 vfs_write+0x1ba/0x2a0 ksys_write+0x59/0xd0 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Charged to offlined memcg libpod-conmon-e59cc83faf807bacc61223fec6a80c1540ebe8f83c802870c6af4708d58f77ea So the page was not freed because it was part of a shmem segment. That is useful information that can help users to diagnose similar problems. Waiman Long (2): mm/page_owner: Introduce SNPRINTF() macro that includes length error check mm/page_owner: Dump memcg information mm/page_owner.c | 76 ++++++++++++++++++++++++++++++++----------------- 1 file changed, 50 insertions(+), 26 deletions(-)