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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 A1975C2D0E7 for ; Fri, 27 Mar 2020 06:37:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 74CF220663 for ; Fri, 27 Mar 2020 06:37:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cJdCotUc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727173AbgC0GhC (ORCPT ); Fri, 27 Mar 2020 02:37:02 -0400 Received: from mail-pg1-f202.google.com ([209.85.215.202]:48848 "EHLO mail-pg1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726275AbgC0GhB (ORCPT ); Fri, 27 Mar 2020 02:37:01 -0400 Received: by mail-pg1-f202.google.com with SMTP id f14so7082007pgj.15 for ; Thu, 26 Mar 2020 23:37:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=UZny7bnt0bQGI998CsHXZqWL0Rqu9hu+FrrOAg2I77w=; b=cJdCotUcZtWbVHPhGaXD5teSu3UkTjbhZAqngFMXWPdNVXmULO1dFihQKTKjSMwmQ/ OGik+coJxS/LgrAIDDBJWWhWIIjEdgIUR66UUVZvW36azleyD65ln1hTSPs18ZUn5SY5 sYrXVNpOVkA9Qg01hn1opZJML4DctdDub5WedENwjseKYMqvGlQjc0xlG3bVxHv3er4V /roJn7lBnenQuxCLGIoNsxWqdeyevN+FXznG+3FoWUSIdLeqjQDMFYx791/h6+YQcf1N M9NiIYNsExiKyBDzyDjXfWbNAMQmzbgtRz77+6kyYpLd8N2vM/M9pSOcIgk8D894t6Xv yxEg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=UZny7bnt0bQGI998CsHXZqWL0Rqu9hu+FrrOAg2I77w=; b=txpADy0OLypLKo4vrUB94yoKLpKX2SKCCKXvPmXb0IM+oTveXbL0JSIDgzZUDGOfvx PPAgZq8tmDzwBFs6vel4VhgHYg6ovt0NMjEJMscWSEmtZPCCQ+gkQTJGnf3WzBeSX1hR hMViTK8ajBvQ30tSuhSwHwDIVwXt6Ylat3Q4w7og5KQuO13KY71bWDpuAv/jhH061N9u 0IKK7cXbZgsBsBgzPU4c4sQ4MDsDxrNb6Mpe9OWTn3sboEBRbW12q6VIm4Pgkq7gxm3W 2EhBdgMb0IB0F5/atTKRBs/7pAS4ciF6acAhhO3dVYtuXYnHko3m3/MhZSrPPM2vPfP7 B5Mw== X-Gm-Message-State: ANhLgQ1PZ9MkaoiqQVa26gts+VJcTtdVBKBDCC8hgE0ZSDExhzYGSvcM 4Se+58ljyNNgHoW52Yte/sUEkG5FhipH X-Google-Smtp-Source: ADFU+vs6s4o+If+CC8QuO35enWvTEoxf9k6L8LTTGFbwjChp7bGIm7jl8Zd6bGB1Gr57Z3HEMXsZlHyI2Vey X-Received: by 2002:a17:90a:1b42:: with SMTP id q60mr4329753pjq.84.1585291020746; Thu, 26 Mar 2020 23:37:00 -0700 (PDT) Date: Thu, 26 Mar 2020 23:36:51 -0700 Message-Id: <20200327063651.146969-1-irogers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.25.1.696.g5e7596f4ac-goog Subject: [PATCH] perf synthetic-events: save 4kb from 2 stack frames From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-kernel@vger.kernel.org Cc: Stephane Eranian , Ian Rogers Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Reduce the scope of PATH_MAX sized char buffers so that the compiler can overlap their usage. perf_event__synthesize_mmap_events before 'sub $0x45b8,%rsp' after 'sub $0x35b8,%rsp'. perf_event__get_comm_ids before 'sub $0x2028,%rsp' after 'sub $0x1028,%rsp'. Signed-off-by: Ian Rogers --- tools/perf/util/synthetic-events.c | 46 ++++++++++++++++++------------ 1 file changed, 27 insertions(+), 19 deletions(-) diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c index 3f28af39f9c6..9ff54707bb30 100644 --- a/tools/perf/util/synthetic-events.c +++ b/tools/perf/util/synthetic-events.c @@ -70,7 +70,6 @@ int perf_tool__process_synth_event(struct perf_tool *tool, static int perf_event__get_comm_ids(pid_t pid, char *comm, size_t len, pid_t *tgid, pid_t *ppid) { - char filename[PATH_MAX]; char bf[4096]; int fd; size_t size = 0; @@ -80,12 +79,16 @@ static int perf_event__get_comm_ids(pid_t pid, char *comm, size_t len, *tgid = -1; *ppid = -1; - snprintf(filename, sizeof(filename), "/proc/%d/status", pid); + { + char filename[PATH_MAX]; - fd = open(filename, O_RDONLY); - if (fd < 0) { - pr_debug("couldn't open %s\n", filename); - return -1; + snprintf(filename, sizeof(filename), "/proc/%d/status", pid); + + fd = open(filename, O_RDONLY); + if (fd < 0) { + pr_debug("couldn't open %s\n", filename); + return -1; + } } n = read(fd, bf, sizeof(bf) - 1); @@ -280,7 +283,6 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, struct machine *machine, bool mmap_data) { - char filename[PATH_MAX]; FILE *fp; unsigned long long t; bool truncation = false; @@ -292,18 +294,22 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, if (machine__is_default_guest(machine)) return 0; - snprintf(filename, sizeof(filename), "%s/proc/%d/task/%d/maps", - machine->root_dir, pid, pid); +#define FILENAME_FMT_STRING "%s/proc/%d/task/%d/maps" + { + char filename[PATH_MAX]; - fp = fopen(filename, "r"); - if (fp == NULL) { - /* - * We raced with a task exiting - just return: - */ - pr_debug("couldn't open %s\n", filename); - return -1; - } + snprintf(filename, sizeof(filename), FILENAME_FMT_STRING, + machine->root_dir, pid, pid); + fp = fopen(filename, "r"); + if (fp == NULL) { + /* + * We raced with a task exiting - just return: + */ + pr_debug("couldn't open %s\n", filename); + return -1; + } + } event->header.type = PERF_RECORD_MMAP2; t = rdclock(); @@ -320,10 +326,10 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, break; if ((rdclock() - t) > timeout) { - pr_warning("Reading %s time out. " + pr_warning("Reading " FILENAME_FMT_STRING " time out. " "You may want to increase " "the time limit by --proc-map-timeout\n", - filename); + machine->root_dir, pid, pid); truncation = true; goto out; } @@ -412,6 +418,8 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, fclose(fp); return rc; + +#undef FILENAME_FMT_STRING } int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t process, -- 2.25.1.696.g5e7596f4ac-goog