From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="gaFHynnw" Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 180DF1BD6 for ; Mon, 27 Nov 2023 14:09:50 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-5d12853cb89so9748507b3.3 for ; Mon, 27 Nov 2023 14:09:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701122989; x=1701727789; darn=vger.kernel.org; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=jTXjNUPwbxQAEQgmTX6mZhuaXcNBEgojUyDX7h5oWL4=; b=gaFHynnwMcnRMOSKlWtWX99TjWcgrYlOUg5hj3kibRIit5u3rZHZtDBzwTcH3s44p1 jrcY2LS0XuLUCHUNBAmbtgCxfbujEW+egZh3E9Fm1eMtm9I4lBxGDtiSRDSrjvuoefiK vy5ZW4xMp/+E/XTK1N9NnnhjH72/Q/phwB1XvBOnO0MgLdX5Qp7pfdrfHG9GA5TA0JWK 6R8MSGNgJ79dxjcX8PSrSBPvl1WTjgxI38lBM/uaz0q2EEVK2/q4gbKcmuoWMHruPGvt LsolBCI0l9dxAGJrp3QShhQDfrEeeJ9y1MSnu+gtcwbScqhUvXCYjopNdAr9ym/jNPUc Vs+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701122989; x=1701727789; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=jTXjNUPwbxQAEQgmTX6mZhuaXcNBEgojUyDX7h5oWL4=; b=rNyjxvmFJ3owRFeyVKWqr3tSVcrah3brHJmyep7FbcYA6bTJASqj6r8mP0CGrRyD6z FGxD9tXtyeIWLLaKubM052DNbMRKaLq5UjqKfszk/U+hmsMejT2BeJv3PllHxYFGyvTE +oOayIhFpvfShaYL7o6V1SZJCHdOJKguTsYiSEKRA37cmIX36Ud23qRPIRsnyZSQDp6W mSTWRFdwHrsfq+5Cv9Ih2dBkGR7ci1aSWHQM/8qWI4D12dGft9fOzRkK8DSw8sg8OPAr FclMxhO7w6pNrtf8pPV+tagMpLJrEaLChlvlw2chpFmhCImhRV+zdR0PHQYCq+0D1zh1 yC8Q== X-Gm-Message-State: AOJu0Yzj5HCTzE3XBhs3lDcRgd0BRs+wUI3IeUIAWHDJw4ta+D5a9WOx WP3oFjIJsSUL3Lnl1ZCVp1/bJatUyqz4 X-Google-Smtp-Source: AGHT+IFkUH1ezGScaVKIf2YW5rYtSWPzFdtRJ2PPO8tpyodcdiEAUOOg8jRQ1N1tVpIi1px37r7gN1f6wAY2 X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:829:6e77:9093:f39b]) (user=irogers job=sendgmr) by 2002:a81:be14:0:b0:5d0:a744:7194 with SMTP id i20-20020a81be14000000b005d0a7447194mr137899ywn.2.1701122989163; Mon, 27 Nov 2023 14:09:49 -0800 (PST) Date: Mon, 27 Nov 2023 14:08:23 -0800 In-Reply-To: <20231127220902.1315692-1-irogers@google.com> Message-Id: <20231127220902.1315692-12-irogers@google.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231127220902.1315692-1-irogers@google.com> X-Mailer: git-send-email 2.43.0.rc1.413.gea7ed67945-goog Subject: [PATCH v5 11/50] perf events: Remove scandir in thread synthesis From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Nick Terrell , Kan Liang , Andi Kleen , Kajol Jain , Athira Rajeev , Huacai Chen , Masami Hiramatsu , Vincent Whitchurch , "Steinar H. Gunderson" , Liam Howlett , Miguel Ojeda , Colin Ian King , Dmitrii Dolgov <9erthalion6@gmail.com>, Yang Jihong , Ming Wang , James Clark , K Prateek Nayak , Sean Christopherson , Leo Yan , Ravi Bangoria , German Gomez , Changbin Du , Paolo Bonzini , Li Dong , Sandipan Das , liuwenyu , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Guilherme Amadio Content-Type: text/plain; charset="UTF-8" This avoids scanddir reading the directory into memory that's allocated and instead allocates on the stack. Signed-off-by: Ian Rogers --- tools/perf/util/synthetic-events.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c index a0579c7d7b9e..7cc38f2a0e9e 100644 --- a/tools/perf/util/synthetic-events.c +++ b/tools/perf/util/synthetic-events.c @@ -38,6 +38,7 @@ #include /* To get things like MAP_HUGETLB even on older libc headers */ #include #include +#include #include #include #include @@ -751,10 +752,10 @@ static int __event__synthesize_thread(union perf_event *comm_event, bool needs_mmap, bool mmap_data) { char filename[PATH_MAX]; - struct dirent **dirent; + struct io_dir iod; + struct io_dirent64 *dent; pid_t tgid, ppid; int rc = 0; - int i, n; /* special case: only send one comm event using passed in pid */ if (!full) { @@ -786,16 +787,19 @@ static int __event__synthesize_thread(union perf_event *comm_event, snprintf(filename, sizeof(filename), "%s/proc/%d/task", machine->root_dir, pid); - n = scandir(filename, &dirent, filter_task, NULL); - if (n < 0) - return n; + io_dir__init(&iod, open(filename, O_CLOEXEC | O_DIRECTORY | O_RDONLY)); + if (iod.dirfd < 0) + return -1; - for (i = 0; i < n; i++) { + while ((dent = io_dir__readdir(&iod)) != NULL) { char *end; pid_t _pid; bool kernel_thread = false; - _pid = strtol(dirent[i]->d_name, &end, 10); + if (!isdigit(dent->d_name[0])) + continue; + + _pid = strtol(dent->d_name, &end, 10); if (*end) continue; @@ -829,9 +833,7 @@ static int __event__synthesize_thread(union perf_event *comm_event, } } - for (i = 0; i < n; i++) - zfree(&dirent[i]); - free(dirent); + close(iod.dirfd); return rc; } -- 2.43.0.rc1.413.gea7ed67945-goog