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=-14.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=no 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 24BB6C4727E for ; Wed, 7 Oct 2020 18:44:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C3C6021775 for ; Wed, 7 Oct 2020 18:44:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="YQmXL1IZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728143AbgJGSoO (ORCPT ); Wed, 7 Oct 2020 14:44:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726388AbgJGSoL (ORCPT ); Wed, 7 Oct 2020 14:44:11 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3523DC061755 for ; Wed, 7 Oct 2020 11:44:10 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id n13so3038741ybk.9 for ; Wed, 07 Oct 2020 11:44:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:message-id:mime-version:subject:from:to:cc; bh=zaTrRhcNQbiBSpttX9+h0ylDutyOhlEu02pPakoZbW0=; b=YQmXL1IZZfWvBoigW7dnIOCgKdPdKbs1IAN19ARXkt7TgYzwNcEC2yEsvc5FjOWAkp CKmwEH6f+lh1SbFEMeLVJoaJe7M/SwbpvDvHfXA5cRclXz5oME2rL7DascOisCpTzalG I0D4L1Jf5J93lTvfG6HnetmqyGHn0zb0qWXtMlZO9xkHCXMG/tHP7KGQTct4c6QcmJii aA4u0rbJ59m5ayhtR+gDpMF3cbIBH+OVAncil2i0XVTAvswL5a2sD+BetVSR6TJHFfYK e15+Ng5AWijdmur7mDmiydhceia3L1KdV2R+/BSlqL5GEILZ5ZpF2edZUee0Sna7J48w RlPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:message-id:mime-version:subject:from :to:cc; bh=zaTrRhcNQbiBSpttX9+h0ylDutyOhlEu02pPakoZbW0=; b=aK8WMZstMnJh+npKbRhGb93BLiyU4+GcTJ/MRQqVC2CQM3WZoUAnLP54r1I+OA047e MRzQwow53PgEuWIeOr7L42QMYVHbD+vOG4xrwsfGXAfFM3xhwAHiqIoden4yDkktfnc7 H/v+WoayC0Df0UfZEkb4BQo40wgXTKx5mzi5zPLkaks4gSyYs9QmlNUqc/honM7aWra+ VxzK5Kl7l5Yl1Iyjeusz8Bk6+uEFjKIk+Z20GdihPpWQND7STfJKUnCnkfKgZ5ZUnW3X cWzrLBL7VCZKUWs8nB6tZFPPh9lbyAII+r6LczdbZ3VI3E2DTGGBgmWRvcOUEy7lMpZO cq2A== X-Gm-Message-State: AOAM531vwHWpbruZE60XDhN50XbXPstKxB2vjPXBrpC99d5bkjQPPDMr 0rtmzFQ9/ioGJgv/m9rkgqQ7DD04ygbaBl1FNl0/ X-Google-Smtp-Source: ABdhPJyAOvITISF0mCmeqoWdYBJRP5GPqkaRIfi/Wq6RwIQm9LoTCHtGG3kUbh6S6DCeTSQ8dqoqRMpGoRWyqTPxreXV Sender: "axelrasmussen via sendgmr" X-Received: from ajr0.svl.corp.google.com ([2620:15c:2cd:203:f693:9fff:feef:c8f8]) (user=axelrasmussen job=sendgmr) by 2002:a25:6811:: with SMTP id d17mr5719921ybc.62.1602096249437; Wed, 07 Oct 2020 11:44:09 -0700 (PDT) Date: Wed, 7 Oct 2020 11:44:01 -0700 Message-Id: <20201007184403.1902111-1-axelrasmussen@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.28.0.806.g8561365e88-goog Subject: [PATCH v2 0/2] Add tracepoints around mmap_lock acquisition From: Axel Rasmussen To: Steven Rostedt , Ingo Molnar , Andrew Morton , Michel Lespinasse , Vlastimil Babka , Daniel Jordan , Laurent Dufour , Axel Rasmussen , Jann Horn , Chinwen Chang Cc: Yafang Shao , linux-kernel@vger.kernel.org, linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patchset adds tracepoints around mmap_lock acquisition. This is useful so we can measure the latency of lock acquisition, in order to detect contention. This version is based upon linux-next (since it depends on some recently-merged patches [1] [2]), and incorporates feedback from the review of the previous version: - Functions renamed to reserve the "trace_" prefix for actual tracepoints. - We no longer measure the duration directly. Instead, users are expected to construct a synthetic event which computes the interval between "start locking" and "acquire returned". - The new helper for checking if tracepoints are enabled in a header is used to avoid un-inlining any of the lock wrappers. This yields ~zero overhead if the tracepoints aren't enabled, and therefore obviates the need for a Kconfig for this change. [1] https://lore.kernel.org/patchwork/patch/1316922/ [2] https://lore.kernel.org/patchwork/patch/1311996/ Axel Rasmussen (2): tracing: support "bool" type in synthetic trace events mmap_lock: add tracepoints around lock acquisition include/linux/mmap_lock.h | 112 +++++++++++++++++++++++++++--- include/trace/events/mmap_lock.h | 70 +++++++++++++++++++ kernel/trace/trace_events_synth.c | 4 ++ mm/Makefile | 2 +- mm/mmap_lock.c | 87 +++++++++++++++++++++++ 5 files changed, 265 insertions(+), 10 deletions(-) create mode 100644 include/trace/events/mmap_lock.h create mode 100644 mm/mmap_lock.c -- 2.28.0.806.g8561365e88-goog