From nobody Tue Feb 10 22:15:27 2026 Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6809D1DE2C0 for ; Fri, 7 Feb 2025 23:25:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738970706; cv=none; b=lo5Q41QmdsK237pXi7rtKS+e02hfAxvC4MiPpIsIB/5/kkyEX1zFNVNOjAJ97zt/Lj1DEFJoqX3jhuJA8nzRvrRF32+41EY8Dxuu1PzPYM0hWBaxKd2qiX1Kvt0Yv87DVyKSsu+G6JGwAsh2EwJ4S38aeiObHuG+JiRr3yKVMAo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738970706; c=relaxed/simple; bh=svnWEsdd0RH2EO1mazYA60VXYRHZD9wTFEGGdpTDYK8=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=DtR2pMjxt9Gmt3aF+oVmhhU99nC9DkxHQVmPimYdevzbbSsx6FvAf9ZFkGtfPdFuCb3sC4IkD0sq6PEJuv3WPxar4JsgBT/jU+EZrFLiMYlQG+cz5M3dNzOpo86P9iXdrIWqINQACzcyAwQxiBObBtQx7/TewqgDWdj66ZVUKAQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=c7uimYUq; arc=none smtp.client-ip=209.85.128.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="c7uimYUq" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-6f2793679ebso30029367b3.0 for ; Fri, 07 Feb 2025 15:25:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1738970703; x=1739575503; 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=zThM502oWmZskuFWvBnh7q8yzaYbumd3GHoPECBIme8=; b=c7uimYUqUz1SCg9xdE8CTixSK81zAcv+tZAPoX8kpdT3BpKTfRetHwsMev9GvNveaN qvpo5+PN97Qr24SYRawoeiX3Ebrrq6jj7qKN1GUuoqf/T9ygz72PhMwHyGn8MzjRLZYk 74ZAUOj6Kpl021d1yNkoK8pkru3a6m28iTwKxDYJvJnh6DbTYQiUZH99D9sdjO3oOP+l HEM9avxYmvRKHhskrmtcSzFWzNnSXcbds6APZcA6wJ0k0ADMUoeg40JxrpRKxXACdnfP lBYwig11/A33xNBynwLQo8ekcnk4P3xbkWXL2NuRx2BWITzbR0Mt6CqvmFBoRX83pRhE ozDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738970703; x=1739575503; 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=zThM502oWmZskuFWvBnh7q8yzaYbumd3GHoPECBIme8=; b=Ydvju0mtqzF++DOjIdCgOc/8AFkuli/86LgkDC9fiu1T21NK6a5/BeCzuxSFPkxL32 wFIx+gDBUEJl7gPT2MhFYjqvRMER3EggVYNoKr70n17tD3nJ01u1Luw5OBA0UI5phFU2 OX/0ssY3pITeYb7/X5+jMQrDYYkyQ+fgxUlNv0iJZPs7aQeYE0skg0J3hXvbVhtYmAHd 5X6hJvGymrPWeTfH/docNnpDxsYp8KhrPsY0xheqrOChVO+BmCJx5p/TPWtDZEmQlurh uQkE4IJ0L1TQx18oCz7qnEJM1ClYiaIAoDvvDLpPi6iY8XuJjMwph7XYYBkiKkg1Mxis IzBQ== X-Forwarded-Encrypted: i=1; AJvYcCXw+TuavqepAN+0huRYR04BCF3hicLkp9hcqb3Hn2abaNNkZlDpcDB/gPPT7iYTsyzPRIqCYRVvEs154r4=@vger.kernel.org X-Gm-Message-State: AOJu0YyHLvcgVqiGtc0tCT+HKvsheVZwfUfZqB+K6SegnkNttYATvcw8 evojc+WeISM0fuAZKcgkeH1zlybJjJX7+zy+BEujkYKIgpFlyzrOLrEK0IiW7owcjcKv4jYZTNf h4BQS6A== X-Google-Smtp-Source: AGHT+IFAhE/XkHhwi5uq3vCpmrpZE+Y0JWgUbIMBDiq2rNgMaOB6aOCcctu3WZpW4W+A+Y+gQnTMvb2kVcM0 X-Received: from irogers.svl.corp.google.com ([2620:15c:2c5:11:79e4:4a45:1e80:ace5]) (user=irogers job=sendgmr) by 2002:a05:6902:726:b0:e5b:4651:ad0c with SMTP id 3f1490d57ef6-e5b4651adbamr47032276.3.1738970703232; Fri, 07 Feb 2025 15:25:03 -0800 (PST) Date: Fri, 7 Feb 2025 15:24:44 -0800 In-Reply-To: <20250207232452.994822-1-irogers@google.com> Message-Id: <20250207232452.994822-4-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250207232452.994822-1-irogers@google.com> X-Mailer: git-send-email 2.48.1.502.g6dc24dfdaf-goog Subject: [PATCH v2 3/7] perf pmu: Switch to io_dir__readdir From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Sam James , Jesper Juhl , James Clark , Zhongqiu Han , Yicong Yang , Thomas Richter , Michael Petlan , Veronika Molnarova , Anne Macedo , Dominique Martinet , Jean-Philippe Romain , Junhao He , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, "=?UTF-8?q?Krzysztof=20=C5=81opatowski?=" Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Avoid DIR allocations when scanning sysfs by using io_dir for the readdir implementation, that allocates about 1kb on the stack. Acked-by: Namhyung Kim Signed-off-by: Ian Rogers --- tools/perf/util/pmu.c | 46 +++++++++++++++++------------------------- tools/perf/util/pmus.c | 30 ++++++++++----------------- 2 files changed, 30 insertions(+), 46 deletions(-) diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index c2a15b0259cf..91ed909433cc 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -195,19 +196,17 @@ static void perf_pmu_format__load(const struct perf_p= mu *pmu, struct perf_pmu_fo */ static int perf_pmu__format_parse(struct perf_pmu *pmu, int dirfd, bool ea= ger_load) { - struct dirent *evt_ent; - DIR *format_dir; + struct io_dirent64 *evt_ent; + struct io_dir format_dir; int ret =3D 0; =20 - format_dir =3D fdopendir(dirfd); - if (!format_dir) - return -EINVAL; + io_dir__init(&format_dir, dirfd); =20 - while ((evt_ent =3D readdir(format_dir)) !=3D NULL) { + while ((evt_ent =3D io_dir__readdir(&format_dir)) !=3D NULL) { struct perf_pmu_format *format; char *name =3D evt_ent->d_name; =20 - if (!strcmp(name, ".") || !strcmp(name, "..")) + if (io_dir__is_dir(&format_dir, evt_ent)) continue; =20 format =3D perf_pmu__new_format(&pmu->format, name); @@ -234,7 +233,7 @@ static int perf_pmu__format_parse(struct perf_pmu *pmu,= int dirfd, bool eager_lo } } =20 - closedir(format_dir); + close(format_dir.dirfd); return ret; } =20 @@ -635,14 +634,12 @@ static inline bool pmu_alias_info_file(const char *na= me) */ static int __pmu_aliases_parse(struct perf_pmu *pmu, int events_dir_fd) { - struct dirent *evt_ent; - DIR *event_dir; + struct io_dirent64 *evt_ent; + struct io_dir event_dir; =20 - event_dir =3D fdopendir(events_dir_fd); - if (!event_dir) - return -EINVAL; + io_dir__init(&event_dir, events_dir_fd); =20 - while ((evt_ent =3D readdir(event_dir))) { + while ((evt_ent =3D io_dir__readdir(&event_dir))) { char *name =3D evt_ent->d_name; int fd; FILE *file; @@ -674,7 +671,6 @@ static int __pmu_aliases_parse(struct perf_pmu *pmu, in= t events_dir_fd) fclose(file); } =20 - closedir(event_dir); pmu->sysfs_aliases_loaded =3D true; return 0; } @@ -2221,10 +2217,9 @@ static void perf_pmu__del_caps(struct perf_pmu *pmu) */ int perf_pmu__caps_parse(struct perf_pmu *pmu) { - struct stat st; char caps_path[PATH_MAX]; - DIR *caps_dir; - struct dirent *evt_ent; + struct io_dir caps_dir; + struct io_dirent64 *evt_ent; int caps_fd; =20 if (pmu->caps_initialized) @@ -2235,24 +2230,21 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu) if (!perf_pmu__pathname_scnprintf(caps_path, sizeof(caps_path), pmu->name= , "caps")) return -1; =20 - if (stat(caps_path, &st) < 0) { + caps_fd =3D open(caps_path, O_CLOEXEC | O_DIRECTORY | O_RDONLY); + if (caps_fd =3D=3D -1) { pmu->caps_initialized =3D true; return 0; /* no error if caps does not exist */ } =20 - caps_dir =3D opendir(caps_path); - if (!caps_dir) - return -EINVAL; - - caps_fd =3D dirfd(caps_dir); + io_dir__init(&caps_dir, caps_fd); =20 - while ((evt_ent =3D readdir(caps_dir)) !=3D NULL) { + while ((evt_ent =3D io_dir__readdir(&caps_dir)) !=3D NULL) { char *name =3D evt_ent->d_name; char value[128]; FILE *file; int fd; =20 - if (!strcmp(name, ".") || !strcmp(name, "..")) + if (io_dir__is_dir(&caps_dir, evt_ent)) continue; =20 fd =3D openat(caps_fd, name, O_RDONLY); @@ -2274,7 +2266,7 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu) fclose(file); } =20 - closedir(caps_dir); + close(caps_fd); =20 pmu->caps_initialized =3D true; return pmu->nr_caps; diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c index 8a0a919415d4..afd59d678fd0 100644 --- a/tools/perf/util/pmus.c +++ b/tools/perf/util/pmus.c @@ -3,10 +3,10 @@ #include #include #include +#include #include #include #include -#include #include #include #include @@ -235,20 +235,16 @@ static void pmu_read_sysfs(unsigned int to_read_types) =20 if (to_read_types & (PERF_TOOL_PMU_TYPE_PE_CORE_MASK | PERF_TOOL_PMU_TYPE= _PE_OTHER_MASK)) { int fd =3D perf_pmu__event_source_devices_fd(); - DIR *dir; - struct dirent *dent; + struct io_dir dir; + struct io_dirent64 *dent; bool core_only =3D (to_read_types & PERF_TOOL_PMU_TYPE_PE_OTHER_MASK) = =3D=3D 0; =20 if (fd < 0) goto skip_pe_pmus; =20 - dir =3D fdopendir(fd); - if (!dir) { - close(fd); - goto skip_pe_pmus; - } + io_dir__init(&dir, fd); =20 - while ((dent =3D readdir(dir))) { + while ((dent =3D io_dir__readdir(&dir)) !=3D NULL) { if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, "..")) continue; if (core_only && !is_pmu_core(dent->d_name)) @@ -257,7 +253,7 @@ static void pmu_read_sysfs(unsigned int to_read_types) perf_pmu__find2(fd, dent->d_name); } =20 - closedir(dir); + close(fd); } skip_pe_pmus: if ((to_read_types & PERF_TOOL_PMU_TYPE_PE_CORE_MASK) && list_empty(&core= _pmus)) { @@ -721,8 +717,8 @@ bool perf_pmus__supports_extended_type(void) char *perf_pmus__default_pmu_name(void) { int fd; - DIR *dir; - struct dirent *dent; + struct io_dir dir; + struct io_dirent64 *dent; char *result =3D NULL; =20 if (!list_empty(&core_pmus)) @@ -732,13 +728,9 @@ char *perf_pmus__default_pmu_name(void) if (fd < 0) return strdup("cpu"); =20 - dir =3D fdopendir(fd); - if (!dir) { - close(fd); - return strdup("cpu"); - } + io_dir__init(&dir, fd); =20 - while ((dent =3D readdir(dir))) { + while ((dent =3D io_dir__readdir(&dir)) !=3D NULL) { if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, "..")) continue; if (is_pmu_core(dent->d_name)) { @@ -747,7 +739,7 @@ char *perf_pmus__default_pmu_name(void) } } =20 - closedir(dir); + close(fd); return result ?: strdup("cpu"); } =20 --=20 2.48.1.502.g6dc24dfdaf-goog