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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 D7A93C433EF for ; Fri, 24 Sep 2021 06:46:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD75060F13 for ; Fri, 24 Sep 2021 06:46:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244275AbhIXGsC (ORCPT ); Fri, 24 Sep 2021 02:48:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244211AbhIXGsA (ORCPT ); Fri, 24 Sep 2021 02:48:00 -0400 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C315C061574; Thu, 23 Sep 2021 23:46:28 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id m26so8085609pff.3; Thu, 23 Sep 2021 23:46:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=f0GxVaNbVW0DvbjS40nByrp5JbLVkqcqCJ/2Z3nsHrQ=; b=KumeSPyep1PPko2skk0eqpAVVSFetiWqeAAclpxM6br9aBNY8UZ8HoRNhWJt6dq4l7 DRGK4F0m1dv7vyCNkpWdtUDJyDW+hkyAAlj3zMFof7bL81tqd8GDGjD90+ALVa+4UYUf 6FMs2h5X4jYNZ3iPHrGfooduiRDtrbu/taZ/wFQWushFmSxXf0ZsHKUup+5eZnOsl0KB 1VSbhX833c7Iy64o+my5fT3ImlXC9hJ88ZWfrLkL0CEcTzp2SMYINwUi4srGg4hk6KZ9 kfjY4T8MD/aNuc51L+/6neQbOOfxq9CcLzOxvs1HIpwVUOJ2DKNRd40CaSm1ws8GpnJw Euew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=f0GxVaNbVW0DvbjS40nByrp5JbLVkqcqCJ/2Z3nsHrQ=; b=g+W2jB6nznB/at/pmx/iC6S1PhwhVBjy7nKWjiPYRE/k6NOcNYa8/3P2r1OoofnK9L gcpOZNuKOb8y3ntb1nJkVonfEbky0NC6BTh2ux8gkQ05R6q5TwjcUHflcgWDxwl+hd2e Ohj2CTHW1h5KPnvJLGrDjEsxfjFj5wZrWhZpI1ERjOm3KP1eE6accRua6NQ4dteMs8yd g8e7je70bfchIzvChZ3ffBE66+bfuy6SCdEqYzNUQJ7dSSpAHaOBf0zAxZSMdbsq6Up1 8Q2Dhy0TjVYNsNLE1jUQFR07r9PLgKnL4G38VGr1jFLiMaRJy/J87eG05I2zTrJPUvsX f0YA== X-Gm-Message-State: AOAM532ngHTOYzK4hz8n143TDqYGudd6LzhSDUx0242lj6jDR1e2CgsA +CBdMYGt1Cp1ldWk7chugXbAAoaZHWhGow== X-Google-Smtp-Source: ABdhPJy4MKlz14srcviUr/+8Aipp+9PwQ1diUE7a6FKNXV3qce1UNzEw7NlbEofTk75dvMF6gWo9ww== X-Received: by 2002:a65:6251:: with SMTP id q17mr2499581pgv.416.1632465987869; Thu, 23 Sep 2021 23:46:27 -0700 (PDT) Received: from VM-0-3-centos.localdomain ([101.32.213.191]) by smtp.gmail.com with ESMTPSA id q20sm7978818pfc.57.2021.09.23.23.46.26 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 23 Sep 2021 23:46:27 -0700 (PDT) From: brookxu To: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Subject: [PATCH 2/2] mem_cgroup: introduce foreign_writeback_in_process() function Date: Fri, 24 Sep 2021 14:46:23 +0800 Message-Id: <1632465983-30525-2-git-send-email-brookxu.cn@gmail.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1632465983-30525-1-git-send-email-brookxu.cn@gmail.com> References: <1632465983-30525-1-git-send-email-brookxu.cn@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chunguang Xu Directly use atomic_read(&frn->done.cnt) == 1 to check whether frn is issued, which makes the code a bit obscure. Maybe we should replace it with a more understandable function. Signed-off-by: Chunguang Xu --- mm/memcontrol.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 3e1384a6..464745b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4542,6 +4542,12 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, * As being wrong occasionally doesn't matter, updates and accesses to the * records are lockless and racy. */ + +static inline bool foreign_writeback_in_process(struct memcg_cgwb_frn *frn) +{ + return atomic_read(&frn->done.cnt) != 1; +} + void mem_cgroup_track_foreign_dirty_slowpath(struct page *page, struct bdi_writeback *wb) { @@ -4565,7 +4571,7 @@ void mem_cgroup_track_foreign_dirty_slowpath(struct page *page, frn->memcg_id == wb->memcg_css->id) break; if (time_before64(frn->at, oldest_at) && - atomic_read(&frn->done.cnt) == 1) { + !foreign_writeback_in_process(frn)) { oldest = i; oldest_at = frn->at; } @@ -4612,7 +4618,7 @@ void mem_cgroup_flush_foreign(struct bdi_writeback *wb) * already one in flight. */ if (time_after64(frn->at, now - intv) && - atomic_read(&frn->done.cnt) == 1) { + !foreign_writeback_in_process(frn)) { frn->at = 0; trace_flush_foreign(wb, frn->bdi_id, frn->memcg_id); cgroup_writeback_by_id(frn->bdi_id, frn->memcg_id, -- 1.8.3.1