From patchwork Fri Jan 28 19:56:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 12729014 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 02789C433EF for ; Fri, 28 Jan 2022 19:57:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 402F36B0106; Fri, 28 Jan 2022 14:57:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 363A26B0108; Fri, 28 Jan 2022 14:57:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1DC176B0109; Fri, 28 Jan 2022 14:57:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0030.hostedemail.com [216.40.44.30]) by kanga.kvack.org (Postfix) with ESMTP id 0EFD96B0106 for ; Fri, 28 Jan 2022 14:57:32 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id C6BE79677C for ; Fri, 28 Jan 2022 19:57:31 +0000 (UTC) X-FDA: 79080755502.28.1170543 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf13.hostedemail.com (Postfix) with ESMTP id 79B3820005 for ; Fri, 28 Jan 2022 19:57:31 +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: in-reply-to:in-reply-to:references:references; bh=gRdxpfrhDzN5J2ZCp0or9HoZYV0jMrufVKuIP+ZP2Uo=; b=NrSV1O1bMsCk0Xs3VBRP/14hM8Ca4UMEazRNGuVAMr35xBxJawatRqkKm3q0DJonQSC3Ul KvEEZiWVSDNTN8CFavKo8NWH01UQsXVfHMU98NMFeurptzwCs2nHWzFeZoQpOi8PZJk1zF QsavSGTdj5yMIyTHQ5eD5DjF4PzeH4g= 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-356-GCdYn6EWP_Oq0PMNqG-U-w-1; Fri, 28 Jan 2022 14:57:27 -0500 X-MC-Unique: GCdYn6EWP_Oq0PMNqG-U-w-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 1D37A1083F68; Fri, 28 Jan 2022 19:57:26 +0000 (UTC) Received: from llong.com (unknown [10.22.33.1]) by smtp.corp.redhat.com (Postfix) with ESMTP id EFAE45DB82; Fri, 28 Jan 2022 19:57:24 +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 2/2] mm/page_owner: Dump memcg information Date: Fri, 28 Jan 2022 14:56:42 -0500 Message-Id: <20220128195642.416743-3-longman@redhat.com> In-Reply-To: <20220128195642.416743-1-longman@redhat.com> References: <20220128195642.416743-1-longman@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 79B3820005 X-Stat-Signature: rimipw6w9z3t63ghdm8r1fczkrqoeme4 X-Rspam-User: nil Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=NrSV1O1b; spf=none (imf13.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: 1643399851-869679 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: It was found that a number of offlined memcgs were not freed because they were pinned by some charged pages that were present. Even "echo 1 > /proc/sys/vm/drop_caches" wasn't able to free those pages. These offlined but not freed memcgs tend to increase in number over time with the side effect that percpu memory consumption as shown in /proc/meminfo also increases over time. In order to find out more information about those pages that pin offlined memcgs, the page_owner feature is extended to dump memory cgroup information especially whether the cgroup is offlined or not. Signed-off-by: Waiman Long --- mm/page_owner.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/mm/page_owner.c b/mm/page_owner.c index c52ce9d6bc3b..e5d8c642296b 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include "internal.h" @@ -339,6 +340,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, depot_stack_handle_t handle) { int ret = 0, pageblock_mt, page_mt; + unsigned long __maybe_unused memcg_data; char *kbuf; count = min_t(size_t, count, PAGE_SIZE); @@ -371,6 +373,32 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, "Page has been migrated, last migrate reason: %s\n", migrate_reason_names[page_owner->last_migrate_reason]); +#ifdef CONFIG_MEMCG + /* + * Look for memcg information and print it out + */ + memcg_data = READ_ONCE(page->memcg_data); + if (memcg_data) { + struct mem_cgroup *memcg = page_memcg_check(page); + bool onlined; + char name[80]; + + if (memcg_data & MEMCG_DATA_OBJCGS) + SNPRINTF(kbuf, count, ret, err, "Slab cache page\n"); + + if (!memcg) + goto copy_out; + + onlined = (memcg->css.flags & CSS_ONLINE); + cgroup_name(memcg->css.cgroup, name, sizeof(name) - 1); + SNPRINTF(kbuf, count, ret, err, "Charged %sto %smemcg %s\n", + PageMemcgKmem(page) ? "(via objcg) " : "", + onlined ? "" : "offlined ", name); + } + +copy_out: +#endif + SNPRINTF(kbuf, count, ret, err, "\n"); if (copy_to_user(buf, kbuf, ret))