From patchwork Fri Oct 1 19:00:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Shakeel Butt X-Patchwork-Id: 12531623 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06C78C433EF for ; Fri, 1 Oct 2021 19:01:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 995AA61A57 for ; Fri, 1 Oct 2021 19:01:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 995AA61A57 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 420D694013C; Fri, 1 Oct 2021 15:01:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3D05F940121; Fri, 1 Oct 2021 15:01:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2BF7094013C; Fri, 1 Oct 2021 15:01:00 -0400 (EDT) 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 1CF94940121 for ; Fri, 1 Oct 2021 15:01:00 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id B617D184558F1 for ; Fri, 1 Oct 2021 19:00:59 +0000 (UTC) X-FDA: 78648785838.22.39BB1D3 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) by imf16.hostedemail.com (Postfix) with ESMTP id 6FD04F000369 for ; Fri, 1 Oct 2021 19:00:59 +0000 (UTC) Received: by mail-pg1-f202.google.com with SMTP id n22-20020a6563d6000000b0029261ffde9bso5574223pgv.22 for ; Fri, 01 Oct 2021 12:00:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc:content-transfer-encoding; bh=oA4D6jdogE7b/uxQa2O7tT0f2ZE2oMjI4z42jgRtcc8=; b=CwC2586zm2KkYzc/zO4TibKRvuGJhARCs0kdLQas3WOjM5X9DtAUcCSoLuF/k0hEsf Qud32VB81TbVE69nvAZnu/lgmWXRqUHZu/l5m1DD8yVCvRg2BkOk8Lh03i7d4azOgwpb k24FlBtLBbtPAiKELRevmpnJJOM0fSEVyyEu714vSz7JBVobN4ZXo0ibB2fuHo0v+1zE qkOw61zTfTidMcwKd8zyQSdHVPDEe23/Ls5YK2dVGWsVoV5I6WEIKNQ5M6ko8dRb/Qy8 kzC1BhoUajYaJ6MPwXM67juENfPQvzXTiRCBlfmuSt9qn+6M4EVnyaPf5aYX2hBpKhaX aqcA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc:content-transfer-encoding; bh=oA4D6jdogE7b/uxQa2O7tT0f2ZE2oMjI4z42jgRtcc8=; b=sMQPtU7aOAhDdJHZ4G9+Jkbu7CoIyQ3XHt3lASYIBt+pFI58/hXBZWVGE6sUsb5wNK ix/Xl+4D5nJQyV+UL01T9R/C1xB9dKJa4h2QdyIKLZmol6Nh9z0vGI14C0k1zz5TIb2V vHDtM0SrCsyRueF0EGA4A3hujUSOGnNJTFn2FlluAjvShAvUZnyg7/qw7imhwlPH18Q7 9WGy8yhjzTGgd2doyQ6qEYOvLStzYHe39e09CfYGpq+Ba4SsIlUfCuCA7BVLgado/0Ln p8D42aKDSEHBL03hgo34uFXQCK9Jx4mVEbTwQNV+3K6VeclEnG133kQo5YWyr7qUn0Lq CDhA== X-Gm-Message-State: AOAM530rYlpF52HjNjDLeLkKraznGqgaUM7etX8E1ZSftG5ktjDWzcfJ +e14qQTyVmOVIxeMMbkVwil/t+wbhbJSWQ== X-Google-Smtp-Source: ABdhPJwPCkuJXkhCP4l5CIoXIN1d+5YKvrNGYw0bdo919HksBNmuVFGnfbbFfUCgWYWvrM3bDJKTfBFFUUIeiw== X-Received: from shakeelb.svl.corp.google.com ([2620:15c:2cd:202:af1a:f1cd:5283:aa67]) (user=shakeelb job=sendgmr) by 2002:a17:90b:4ac1:: with SMTP id mh1mr21669147pjb.238.1633114858394; Fri, 01 Oct 2021 12:00:58 -0700 (PDT) Date: Fri, 1 Oct 2021 12:00:40 -0700 In-Reply-To: <20211001190040.48086-1-shakeelb@google.com> Message-Id: <20211001190040.48086-2-shakeelb@google.com> Mime-Version: 1.0 References: <20211001190040.48086-1-shakeelb@google.com> X-Mailer: git-send-email 2.33.0.800.g4c38ced690-goog Subject: [PATCH v2 2/2] memcg: unify memcg stat flushing From: Shakeel Butt To: Johannes Weiner , Michal Hocko Cc: " =?utf-8?q?Michal_Koutn=C3=BD?= " , Andrew Morton , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Shakeel Butt X-Rspamd-Queue-Id: 6FD04F000369 X-Stat-Signature: cbbesrbwewq4rrgoxxnhsf4f8sg8n6tg Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=CwC2586z; spf=pass (imf16.hostedemail.com: domain of 36lpXYQgKCA87wpztt0qv33v0t.r310x29C-11zAprz.36v@flex--shakeelb.bounces.google.com designates 209.85.215.202 as permitted sender) smtp.mailfrom=36lpXYQgKCA87wpztt0qv33v0t.r310x29C-11zAprz.36v@flex--shakeelb.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam06 X-HE-Tag: 1633114859-480736 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: The memcg stats can be flushed in multiple context and potentially in parallel too. For example multiple parallel user space readers for memcg stats will contend on the rstat locks with each other. There is no need for that. We just need one flusher and everyone else can benefit. In addition after aa48e47e3906 ("memcg: infrastructure to flush memcg stats") the kernel periodically flush the memcg stats from the root, so, the other flushers will potentially have much less work to do. Signed-off-by: Shakeel Butt Acked-by: Johannes Weiner Cc: Michal Hocko Cc: "Michal Koutný" Cc: Andrew Morton --- Changelog since v1: - N/A mm/memcontrol.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 25f55636ca37..22d905f30a30 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -638,12 +638,14 @@ static inline void memcg_rstat_updated(struct mem_cgroup *memcg) static void __mem_cgroup_flush_stats(void) { - if (!spin_trylock(&stats_flush_lock)) + unsigned long flag; + + if (!spin_trylock_irqsave(&stats_flush_lock, flag)) return; cgroup_rstat_flush_irqsafe(root_mem_cgroup->css.cgroup); atomic_set(&stats_flush_threshold, 0); - spin_unlock(&stats_flush_lock); + spin_unlock_irqrestore(&stats_flush_lock, flag); } void mem_cgroup_flush_stats(void) @@ -1462,7 +1464,7 @@ static char *memory_stat_format(struct mem_cgroup *memcg) * * Current memory state: */ - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { u64 size; @@ -3566,8 +3568,7 @@ static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) unsigned long val; if (mem_cgroup_is_root(memcg)) { - /* mem_cgroup_threshold() calls here from irqsafe context */ - cgroup_rstat_flush_irqsafe(memcg->css.cgroup); + mem_cgroup_flush_stats(); val = memcg_page_state(memcg, NR_FILE_PAGES) + memcg_page_state(memcg, NR_ANON_MAPPED); if (swap) @@ -3948,7 +3949,7 @@ static int memcg_numa_stat_show(struct seq_file *m, void *v) int nid; struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { seq_printf(m, "%s=%lu", stat->name, @@ -4020,7 +4021,7 @@ static int memcg_stat_show(struct seq_file *m, void *v) BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats)); - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { unsigned long nr; @@ -4523,7 +4524,7 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); struct mem_cgroup *parent; - cgroup_rstat_flush_irqsafe(memcg->css.cgroup); + mem_cgroup_flush_stats(); *pdirty = memcg_page_state(memcg, NR_FILE_DIRTY); *pwriteback = memcg_page_state(memcg, NR_WRITEBACK); @@ -6408,7 +6409,7 @@ static int memory_numa_stat_show(struct seq_file *m, void *v) int i; struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { int nid;