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[49.186.4.237]) by smtp.gmail.com with ESMTPSA id kk5-20020a170903070500b0019a928a8982sm3096849plb.118.2023.03.15.01.49.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Mar 2023 01:49:51 -0700 (PDT) Received: from [192.168.253.23] (helo=devoid.disaster.area) by dread.disaster.area with esmtp (Exim 4.92.3) (envelope-from ) id 1pcMpQ-008zeU-45; Wed, 15 Mar 2023 19:49:48 +1100 Received: from dave by devoid.disaster.area with local (Exim 4.96) (envelope-from ) id 1pcMpQ-00Ag6T-0N; Wed, 15 Mar 2023 19:49:48 +1100 From: Dave Chinner To: linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org Cc: linux-mm@vger.kernel.org, linux-fsdevel@vger.kernel.org, yebin10@huawei.com Subject: [PATCH 3/4] fork: remove use of percpu_counter_sum_all Date: Wed, 15 Mar 2023 19:49:37 +1100 Message-Id: <20230315084938.2544737-4-david@fromorbit.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230315084938.2544737-1-david@fromorbit.com> References: <20230315084938.2544737-1-david@fromorbit.com> MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1760423041255700828?= X-GMAIL-MSGID: =?utf-8?q?1760423041255700828?= From: Dave Chinner This effectively reverts the change made in commit f689054aace2 ("percpu_counter: add percpu_counter_sum_all interface") as the race condition percpu_counter_sum_all() was invented to avoid is now handled directly in percpu_counter_sum() and nobody needs to care about summing racing with cpu unplug anymore. Signed-off-by: Dave Chinner --- kernel/fork.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index d8cda4c6de6c..c0257cbee093 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -755,11 +755,6 @@ static void check_mm(struct mm_struct *mm) for (i = 0; i < NR_MM_COUNTERS; i++) { long x = percpu_counter_sum(&mm->rss_stat[i]); - if (likely(!x)) - continue; - - /* Making sure this is not due to race with CPU offlining. */ - x = percpu_counter_sum_all(&mm->rss_stat[i]); if (unlikely(x)) pr_alert("BUG: Bad rss-counter state mm:%p type:%s val:%ld\n", mm, resident_page_types[i], x);