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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F426C433F5 for ; Fri, 28 Jan 2022 21:31:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A4D7D6B00F4; Fri, 28 Jan 2022 16:31:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9FDB26B00F6; Fri, 28 Jan 2022 16:31:28 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8C4B56B00F7; Fri, 28 Jan 2022 16:31:28 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0167.hostedemail.com [216.40.44.167]) by kanga.kvack.org (Postfix) with ESMTP id 7DF666B00F4 for ; Fri, 28 Jan 2022 16:31:28 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 317AB18215EE2 for ; Fri, 28 Jan 2022 21:31:28 +0000 (UTC) X-FDA: 79080992256.20.A2E1FC6 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf16.hostedemail.com (Postfix) with ESMTP id D4A4518004A for ; Fri, 28 Jan 2022 21:31:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643405486; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cPaaPTwaHnrZy5BBxHC8AwDN/oX7cxF5Nc5fiuL/xAs=; b=L1JMuwJe5kfMqxQiPSc02NKDIsEuZ6FkbEfmxIa0wffJxLyJpgbSZnI9p/c48Kxop+6aEw D6gzfYmDfsvWiyHhND65z6sOuPOOuPs5A0ok1UW44DVqnk7oZ/kq+/yRm/37fZP7B3br5V 83QAaa501fO2h47uoe2EamSZzPrSEi0= 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-70-vIGYNqzuMMah-cPnGiTNJQ-1; Fri, 28 Jan 2022 16:31:23 -0500 X-MC-Unique: vIGYNqzuMMah-cPnGiTNJQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 84FD5814243; Fri, 28 Jan 2022 21:31:21 +0000 (UTC) Received: from [10.22.33.1] (unknown [10.22.33.1]) by smtp.corp.redhat.com (Postfix) with ESMTP id 42AE8E2FE; Fri, 28 Jan 2022 21:31:08 +0000 (UTC) Message-ID: Date: Fri, 28 Jan 2022 16:31:07 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.4.0 Subject: Re: [PATCH 2/2] mm/page_owner: Dump memcg information Content-Language: en-US To: Ira Weiny Cc: Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, Rafael Aquini References: <20220128195642.416743-1-longman@redhat.com> <20220128195642.416743-3-longman@redhat.com> <20220128212249.GI785175@iweiny-DESK2.sc.intel.com> From: Waiman Long In-Reply-To: <20220128212249.GI785175@iweiny-DESK2.sc.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Stat-Signature: za5rikhc4k11mkwyfq1zgjs15beprhqw X-Rspam-User: nil Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=L1JMuwJe; spf=none (imf16.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-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: D4A4518004A X-HE-Tag: 1643405486-303733 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 1/28/22 16:22, Ira Weiny wrote: > On Fri, Jan 28, 2022 at 02:56:42PM -0500, Waiman Long wrote: >> 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", > ^^^ > Extra specifier? > > Did this compile without warnings? Yes, there was no warning. Cheers, Longmna > Ira > >> + PageMemcgKmem(page) ? "(via objcg) " : "", >> + onlined ? "" : "offlined ", name); >> + } >> + >> +copy_out: >> +#endif >> + >> SNPRINTF(kbuf, count, ret, err, "\n"); >> >> if (copy_to_user(buf, kbuf, ret)) >> -- >> 2.27.0 >> >>