From nobody Fri Dec 19 09:29:37 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0BFD2C4167B for ; Thu, 7 Dec 2023 05:05:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230424AbjLGFFE (ORCPT ); Thu, 7 Dec 2023 00:05:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229537AbjLGFEw (ORCPT ); Thu, 7 Dec 2023 00:04:52 -0500 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 2042AD51 for ; Wed, 6 Dec 2023 21:04:58 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-5d8f69da4c8so3960947b3.2 for ; Wed, 06 Dec 2023 21:04:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701925497; x=1702530297; 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=8yddnIh+eN5/+1uKGHF2Xb5nfq0hpynkUoMoJjaaQGg=; b=q34xsdtWe+M02IKvzjOSxgMLzNDMir7y4GddACF4uwS1xLYobrcr5JqQlwvTEbOqFb Bdbni7PR4oS1Ulkd0+x6lLWMNPPUJwZa36paZYHagqkSxsviR5WamB3dpsjoxF2ApD7P A2ue9Dn5U5e2W3RHSm++aMFN3HfhDmg1LpKnfUOj4nOTRmjm533bxa7fXx1yepq0SwGu ivEUDJa9+ij9Hbr8cgTMv1nVubCdxgx64i0quslEc8kyX7itmHLUxMm+Vy2tZVKN0wpk Vq90xrUt21f6EhxVtptXt+VBeu3IDyYjflmWKnCvNRoeH7608C6ZhgFhYMWaLwqNs2yT vjrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701925497; x=1702530297; 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=8yddnIh+eN5/+1uKGHF2Xb5nfq0hpynkUoMoJjaaQGg=; b=Sd018liynRWb7FJ6Ifxysr1ebJ99HxUW2Uh7BLCqX2UuTj9FLrTgxzLEHv9aq5itiw j1cX9h7GyQey41IXU2gdoLVVAc+i1nwPD+o0dLukgJ49YKtFJjUzaS6sgyWkbUcxgfE6 ypx6EbWRFCY3Gezc8b8R7juf7Tdr2R8y+lZ25SSBGtD4S5UMaMHIIgyTevbSq1Ds9VnE rThfd+tRkapTat32TEQqgfviD5JtXcamlSN9U653wYzeTW/XOkfOSsG8u1c4Wo9lvzXo wo6HBW69UIHhb5cLyyYRXDn8M071PPCgQBsDNDaYCAtTsX7ovVNY2TGNKtjnbPtv0bQS CxWA== X-Gm-Message-State: AOJu0YwJ5akEETBEnUxLVPMYo8Xoe77mU345dI1p9mErsZezT8e4xrSu J9KByF9YwRX45YuIA1fE+VUjtBmc4FrB X-Google-Smtp-Source: AGHT+IE882a5TV3lzEwPVuhsbdGQD4YkJ4nM2OZr83LhR4in6R8D9tV/naisyo0LtFoYkBhOxvaSkjr1xQ4u X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:35bf:293e:7696:34e9]) (user=irogers job=sendgmr) by 2002:a25:74d1:0:b0:db4:5e66:4a05 with SMTP id p200-20020a2574d1000000b00db45e664a05mr30614ybc.2.1701925497312; Wed, 06 Dec 2023 21:04:57 -0800 (PST) Date: Wed, 6 Dec 2023 21:04:31 -0800 In-Reply-To: <20231207050433.1426834-1-irogers@google.com> Message-Id: <20231207050433.1426834-5-irogers@google.com> Mime-Version: 1.0 References: <20231207050433.1426834-1-irogers@google.com> X-Mailer: git-send-email 2.43.0.rc2.451.g8631bc7472-goog Subject: [PATCH v1 4/6] perf pmu: Switch to io_dir__readdir From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , "Masami Hiramatsu (Google)" , Thomas Richter , Quentin Monnet , Fangrui Song , Kan Liang , Yanteng Si , K Prateek Nayak , Artem Savkov , James Clark , Ravi Bangoria , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Signed-off-by: Ian Rogers --- tools/perf/util/pmu.c | 48 +++++++++++++++++------------------------- tools/perf/util/pmus.c | 30 ++++++++++---------------- 2 files changed, 30 insertions(+), 48 deletions(-) diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 3c9609944a2f..cddb82123a1e 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -184,19 +185,17 @@ static void perf_pmu_format__load(const struct perf_p= mu *pmu, struct perf_pmu_fo */ int perf_pmu__format_parse(struct perf_pmu *pmu, int dirfd, bool eager_loa= d) { - 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); @@ -223,7 +222,7 @@ int perf_pmu__format_parse(struct perf_pmu *pmu, int di= rfd, bool eager_load) } } =20 - closedir(format_dir); + close(format_dir.dirfd); return ret; } =20 @@ -599,8 +598,8 @@ static inline bool pmu_alias_info_file(const char *name) static int pmu_aliases_parse(struct perf_pmu *pmu) { char path[PATH_MAX]; - struct dirent *evt_ent; - DIR *event_dir; + struct io_dirent64 *evt_ent; + struct io_dir event_dir; size_t len; int fd, dir_fd; =20 @@ -615,13 +614,9 @@ static int pmu_aliases_parse(struct perf_pmu *pmu) return 0; } =20 - event_dir =3D fdopendir(dir_fd); - if (!event_dir){ - close (dir_fd); - return -EINVAL; - } + io_dir__init(&event_dir, 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; FILE *file; =20 @@ -651,7 +646,6 @@ static int pmu_aliases_parse(struct perf_pmu *pmu) fclose(file); } =20 - closedir(event_dir); close (dir_fd); pmu->sysfs_aliases_loaded =3D true; return 0; @@ -1883,10 +1877,9 @@ 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) @@ -1897,24 +1890,21 @@ 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); @@ -1936,7 +1926,7 @@ 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 ce4931461741..65b23b98666b 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 @@ -184,8 +184,8 @@ static int pmus_cmp(void *priv __maybe_unused, static void pmu_read_sysfs(bool core_only) { int fd; - DIR *dir; - struct dirent *dent; + struct io_dir dir; + struct io_dirent64 *dent; =20 if (read_sysfs_all_pmus || (core_only && read_sysfs_core_pmus)) return; @@ -194,13 +194,9 @@ static void pmu_read_sysfs(bool core_only) if (fd < 0) return; =20 - dir =3D fdopendir(fd); - if (!dir) { - close(fd); - return; - } + 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)) @@ -209,7 +205,7 @@ static void pmu_read_sysfs(bool core_only) perf_pmu__find2(fd, dent->d_name); } =20 - closedir(dir); + close(fd); if (list_empty(&core_pmus)) { if (!perf_pmu__create_placeholder_core_pmu(&core_pmus)) pr_err("Failure to set up any core PMUs\n"); @@ -563,8 +559,8 @@ 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)) @@ -574,13 +570,9 @@ 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)) { @@ -589,7 +581,7 @@ char *perf_pmus__default_pmu_name(void) } } =20 - closedir(dir); + close(fd); return result ?: strdup("cpu"); } =20 --=20 2.43.0.rc2.451.g8631bc7472-goog