From patchwork Sat May 8 12:50:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kefeng Wang X-Patchwork-Id: 12246041 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=-16.8 required=3.0 tests=BAYES_00, 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 623E7C43460 for ; Sat, 8 May 2021 12:40:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C4BB461468 for ; Sat, 8 May 2021 12:40:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C4BB461468 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EA1268D0028; Sat, 8 May 2021 08:40:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E51498D001A; Sat, 8 May 2021 08:40:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D18FB8D0028; Sat, 8 May 2021 08:40:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0194.hostedemail.com [216.40.44.194]) by kanga.kvack.org (Postfix) with ESMTP id B1DD78D001A for ; Sat, 8 May 2021 08:40:09 -0400 (EDT) Received: from smtpin33.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 6834D180AD838 for ; Sat, 8 May 2021 12:40:09 +0000 (UTC) X-FDA: 78118021338.33.B1421CE Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) by imf15.hostedemail.com (Postfix) with ESMTP id DDF29A000380 for ; Sat, 8 May 2021 12:40:01 +0000 (UTC) Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Fcmzq42HhzkXPc; Sat, 8 May 2021 20:37:27 +0800 (CST) Received: from localhost.localdomain.localdomain (10.175.113.25) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.498.0; Sat, 8 May 2021 20:39:56 +0800 From: Kefeng Wang To: Andrew Morton , CC: , Kefeng Wang Subject: [PATCH] mm: page-writeback: Kill get_writeback_state() comments Date: Sat, 8 May 2021 20:50:26 +0800 Message-ID: <20210508125026.56600-1-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 X-Originating-IP: [10.175.113.25] X-CFilter-Loop: Reflected Authentication-Results: imf15.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=huawei.com; spf=pass (imf15.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 45.249.212.191 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: DDF29A000380 X-Stat-Signature: t6kbmbozzekoogyejbeworz94x7uezc6 Received-SPF: none (huawei.com>: No applicable sender policy available) receiver=imf15; identity=mailfrom; envelope-from=""; helo=szxga05-in.huawei.com; client-ip=45.249.212.191 X-HE-DKIM-Result: none/none X-HE-Tag: 1620477601-937839 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 get_writeback_state() has gone since 2006, kill related comments. Signed-off-by: Kefeng Wang --- mm/page-writeback.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0062d5c57d41..1bbe185a6524 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1869,10 +1869,9 @@ DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0; * which was newly dirtied. The function will periodically check the system's * dirty state and will initiate writeback if needed. * - * On really big machines, get_writeback_state is expensive, so try to avoid - * calling it too often (ratelimiting). But once we're over the dirty memory - * limit we decrease the ratelimiting by a lot, to prevent individual processes - * from overshooting the limit by (ratelimit_pages) each. + * Once we're over the dirty memory limit we decrease the ratelimiting + * by a lot, to prevent individual processes from overshooting the limit + * by (ratelimit_pages) each. */ void balance_dirty_pages_ratelimited(struct address_space *mapping) { @@ -2045,8 +2044,6 @@ void laptop_sync_completion(void) /* * If ratelimit_pages is too high then we can get into dirty-data overload * if a large number of processes all perform writes at the same time. - * If it is too low then SMP machines will call the (expensive) - * get_writeback_state too often. * * Here we set ratelimit_pages to a level which ensures that when all CPUs are * dirtying in parallel, we cannot go more than 3% (1/32) over the dirty memory