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=-7.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY,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 D894EC2BA2B for ; Mon, 13 Apr 2020 16:54:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B116920780 for ; Mon, 13 Apr 2020 16:54:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586796848; bh=voRofBWt3Bg02puMqNN0CEnYZL5K/hkfznKgWIjtDkg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Rv850anJfUtmx4fkc/oLTLR8qkFT+oemJQV79ZNP/llGe5wI/l2qL1Zk+zbqcPloH 5j8KDNWvgQmFa0mJXmxFsv69kU8XtDmIm3YmMl6GGbLCmMzHoYvbhGyFDBM+AsLjwo +CuSYMjrslTbg6MjxQdwdS/d1Ik983KVeuLMGf1U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732096AbgDMQyH (ORCPT ); Mon, 13 Apr 2020 12:54:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:46628 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732071AbgDMQx6 (ORCPT ); Mon, 13 Apr 2020 12:53:58 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5F3312137B; Mon, 13 Apr 2020 16:53:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586796837; bh=voRofBWt3Bg02puMqNN0CEnYZL5K/hkfznKgWIjtDkg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QPKJrAjJzYfcoQ097RhrY4Wx79skX2q4x/Ol9soQjVB5DA7CNpl576vtPH/U6j5A4 w2J1uUweQTH7prFpfRPNSx6YjttbNxFE9ciDe16ZGeZUi+Y9L0boNZBQWDX79opKNT JKjSMfC49qnS9ygyRFAC5trbiRQRhygRPYKEGdfA= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Ian Rogers , Alexander Shishkin , Andrey Zhizhikin , Jiri Olsa , Kan Liang , Kefeng Wang , Mark Rutland , Peter Zijlstra , Petr Mladek , Stephane Eranian , Arnaldo Carvalho de Melo Subject: [PATCH 21/26] perf synthetic-events: save 4kb from 2 stack frames Date: Mon, 13 Apr 2020 13:51:58 -0300 Message-Id: <20200413165203.1816-22-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200413165203.1816-1-acme@kernel.org> References: <20200413165203.1816-1-acme@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ian Rogers Reuse an existing char buffer to avoid two PATH_MAX sized char buffers. Reduces stack frame sizes by 4kb. 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'. The performance impact of this change is negligible. Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Andrey Zhizhikin Cc: Jiri Olsa Cc: Kan Liang Cc: Kefeng Wang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Petr Mladek Cc: Stephane Eranian Cc: Thomas Gleixner Link: http://lore.kernel.org/lkml/20200402154357.107873-4-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/synthetic-events.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c index a661b122d9d8..9d4aa951eaa6 100644 --- a/tools/perf/util/synthetic-events.c +++ b/tools/perf/util/synthetic-events.c @@ -71,7 +71,6 @@ 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; @@ -81,11 +80,11 @@ 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); + snprintf(bf, sizeof(bf), "/proc/%d/status", pid); - fd = open(filename, O_RDONLY); + fd = open(bf, O_RDONLY); if (fd < 0) { - pr_debug("couldn't open %s\n", filename); + pr_debug("couldn't open %s\n", bf); return -1; } @@ -281,9 +280,9 @@ 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; + char bf[BUFSIZ]; bool truncation = false; unsigned long long timeout = proc_map_timeout * 1000000ULL; int rc = 0; @@ -293,15 +292,15 @@ 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); + snprintf(bf, sizeof(bf), "%s/proc/%d/task/%d/maps", + machine->root_dir, pid, pid); - fp = fopen(filename, "r"); + fp = fopen(bf, "r"); if (fp == NULL) { /* * We raced with a task exiting - just return: */ - pr_debug("couldn't open %s\n", filename); + pr_debug("couldn't open %s\n", bf); return -1; } @@ -309,7 +308,6 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, t = rdclock(); while (1) { - char bf[BUFSIZ]; char prot[5]; char execname[PATH_MAX]; char anonstr[] = "//anon"; @@ -321,10 +319,10 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, break; if ((rdclock() - t) > timeout) { - pr_warning("Reading %s time out. " + pr_warning("Reading %s/proc/%d/task/%d/maps 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; } -- 2.21.1