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[2620:137:e000::1:20]) by mx.google.com with ESMTP id d14-20020a170902cece00b001a1abd9a0a1si16542411plg.313.2023.04.28.11.11.55; Fri, 28 Apr 2023 11:12:12 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=nQwQyaHp; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346048AbjD1Rfk (ORCPT + 99 others); Fri, 28 Apr 2023 13:35:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34442 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229726AbjD1Rfi (ORCPT ); Fri, 28 Apr 2023 13:35:38 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16013E69 for ; Fri, 28 Apr 2023 10:35:38 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-b9a829a3de0so4557240276.2 for ; Fri, 28 Apr 2023 10:35:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1682703337; x=1685295337; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=yyTrtR3S5gMM0KVdMQoSGiM4SzOrc6DI1bOXsYT1q/A=; b=nQwQyaHpYfL58xtHqqBDwedop7h9GVNhO8im6D5ItL5TT3/jAi7ai9In0/BO8VnFDa qkTXUAXDHJ6IqJgFYeuedFEi0Br7UDyk/XAYEoeA3NmhdtOFFHeYWt4LIgKw611NLFHv nD98nj14+oDPx/kUoLmUd8k3EcA5cVJjpf/fvjcHBpwbDNHK+hf7n9qTzAhHQ8N4liEL ytXu9oXNn1PVAz2Uhqm6BmBU9eZOwscjpuw4sWFTElsrGxlI1w18+V1XmPGPDF86TXbX 4ZtOJ7muAxfe37u+4e4pa7vBNb6Mplg2RQR1FUWuydhoM5Dxzyw3mnNVGTyRhien6tMA gwzw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682703337; x=1685295337; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=yyTrtR3S5gMM0KVdMQoSGiM4SzOrc6DI1bOXsYT1q/A=; b=RrYXmDRh4SVr8DQsMzCQ0O8129T9wskTW13h7Q5Krwd1oxawvcapts5lGkSWjgaSrB F4E4hLu2IOc7ZwvCsdpLqpVVNriJo0EsA/XBH4TxWD7YepsF37XAOkiDEs0gzS/eHUeT TsJ1baYgkk1aitezEG1ak2B+I66txXMs5xP3uj3DKwoGOUB3fjtLuyuScrcEpL+Gd6+H ol1KtspCoZinj23VaP8jCfSxMfCMSmseoxvTAKy5Nfespo9h9F355Otu/PTdLBJ3xBnI btGzg8+TvvK/DHGDJT/goEQzWe71vO1+ObfLUItQSgD2XPHb3koJjYtHzMYVC0Hd8FGK 36vA== X-Gm-Message-State: AC+VfDypeobE8JYEBZx9A9LU59gG7X4ZdyJwfyP8YwlJyGmJPtPB5MSy 8D01NuLsMWCSMcTFDHF1R1S0XdXK9A4= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:201:51d6:764:dc11:ffbd]) (user=surenb job=sendgmr) by 2002:a25:84d1:0:b0:b9a:76e4:ccd2 with SMTP id x17-20020a2584d1000000b00b9a76e4ccd2mr2343098ybm.10.1682703337303; Fri, 28 Apr 2023 10:35:37 -0700 (PDT) Date: Fri, 28 Apr 2023 10:35:33 -0700 Mime-Version: 1.0 X-Mailer: git-send-email 2.40.1.495.gc816e09b53d-goog Message-ID: <20230428173533.18158-1-surenb@google.com> Subject: [PATCH 1/1] mm: change per-VMA lock statistics to be disabled by default From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org, lstoakes@gmail.com, vbabka@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@android.com, surenb@google.com X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE,USER_IN_DEF_DKIM_WL 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?1764444113895020213?= X-GMAIL-MSGID: =?utf-8?q?1764444636232772870?= Change CONFIG_PER_VMA_LOCK_STATS to be disabled by default, as most users don't need it. Add configuration help to clarify its usage. Fixes: 52f238653e45 ("mm: introduce per-VMA lock statistics") Suggested-by: Linus Torvalds Signed-off-by: Suren Baghdasaryan Acked-by: Vlastimil Babka Reviewed-by: David Hildenbrand --- mm/Kconfig.debug | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 6dae63b46368..a925415b4d10 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -274,6 +274,12 @@ config DEBUG_KMEMLEAK_AUTO_SCAN config PER_VMA_LOCK_STATS bool "Statistics for per-vma locks" depends on PER_VMA_LOCK - default y help - Statistics for per-vma locks. + Say Y here to enable success, retry and failure counters of page + faults handled under protection of per-vma locks. When enabled, the + counters are exposed in /proc/vmstat. This information is useful for + kernel developers to evaluate effectiveness of per-vma locks and to + identify pathological cases. Counting these events introduces a small + overhead in the page fault path. + + If in doubt, say N.