From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E0CEF170839; Fri, 10 May 2024 14:21:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715350873; cv=none; b=bQqLMbTgR2UbqbEWJ2CCu35Ch5BNHIwt7LWahXvfICKdv3ry2uKjEGv7EKDuJXN//yvr6YhUIZzD82H7se6XzJsM/ZKhdUCHGnh71YEIuRKZrBNmzrAofLnDh6/mo58bfdSDXp+cHCEPBo6d81kNHlecSTGMlN5gAsb3EGUJATQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715350873; c=relaxed/simple; bh=z8w1gqQixZgCovfhHB3pSvSB8T9+CM/mmdXFrbeLlM8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OkYUUt0gVIiKR+Ry5EuzSIaFeoIaYxgcMs8wZ63SoeC9NJZ6JFYlbGuC4BrWt2ZQi3pDBSyVy+sEzzmk7M4aEWAh0hRnEy99qfd/Va1iIhJM6iDOoqfGFgDlxISyKmWdunOLOTc6O0m+pnxwJ7AkM0e+6Q0hRyvoCpld8lE45Ic= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DpEJ5OGt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DpEJ5OGt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A70C2C113CC; Fri, 10 May 2024 14:21:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1715350872; bh=z8w1gqQixZgCovfhHB3pSvSB8T9+CM/mmdXFrbeLlM8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DpEJ5OGthkHzb0Yg0yKT0dzQQ9RWpVdZjkcn771CYuE94r+r2Lg7nPz4U5mKGObUt dCXrDD1oMVT/1ULXFo1RijVpLmvR4SXVo26Ra/vzpXdAeTMktXmEpZvb/2GhPq45sM CszVahHfzRmiscnkbWqE1ymPtGr20/oby7cJwNxLKmbgQC1cQXYj4/c2tb0WKMf4B8 lDumbB6m52sgoaAg8pzv4udw9e8wY3c6yYL2AylNyNRRViOHfJNXzL9jpTSEbChsAS hENev/2ik+qSyIoJg+bd0vIpmlK6BvFuDbXUoFemDQuQwJnIyvt7Y4xIlPb9a/RKsp gHZOEy2uFGSzg== Date: Fri, 10 May 2024 11:21:08 -0300 From: Arnaldo Carvalho de Melo To: Ian Rogers Cc: Peter Zijlstra , Ingo Molnar , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Adrian Hunter , Kan Liang , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1] perf tracepoint: Don't scan all tracepoints to test if one exists Message-ID: References: <20240509060541.1928390-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240509060541.1928390-1-irogers@google.com> On Wed, May 08, 2024 at 11:05:41PM -0700, Ian Rogers wrote: > In is_valid_tracepoint, rather than scanning > "/sys/kernel/tracing/events/*/*" skipping any path where > "/sys/kernel/tracing/events/*/*/id" doesn't exist, and then testing if > "*:*" matches the tracepoint name, just use the given tracepoint name > replace the ':' with '/' and see if the id file exists. This turns a > nested directory search into a single file available test. > > Rather than return 1 for valid and 0 for invalid, return true and > false. > > Signed-off-by: Ian Rogers > --- > tools/perf/util/tracepoint.c | 53 ++++++++++++++---------------------- > tools/perf/util/tracepoint.h | 3 +- > 2 files changed, 23 insertions(+), 33 deletions(-) > > diff --git a/tools/perf/util/tracepoint.c b/tools/perf/util/tracepoint.c > index 92dd8b455b90..cca6808f7951 100644 > --- a/tools/perf/util/tracepoint.c > +++ b/tools/perf/util/tracepoint.c > @@ -4,10 +4,12 @@ > #include > #include > #include > +#include > #include > #include > > #include > +#include "fncache.h" > > int tp_event_has_id(const char *dir_path, struct dirent *evt_dir) > { > @@ -26,39 +28,26 @@ int tp_event_has_id(const char *dir_path, struct dirent *evt_dir) > /* > * Check whether event is in /tracing/events > */ > -int is_valid_tracepoint(const char *event_string) > +bool is_valid_tracepoint(const char *event_string) > { > - DIR *sys_dir, *evt_dir; > - struct dirent *sys_dirent, *evt_dirent; > - char evt_path[MAXPATHLEN]; > - char *dir_path; > - > - sys_dir = tracing_events__opendir(); > - if (!sys_dir) > - return 0; > + char *dst, *path = malloc(strlen(event_string) + 4); /* Space for "/id\0". */ > + const char *src; > + bool have_file; > > - for_each_subsystem(sys_dir, sys_dirent) { > - dir_path = get_events_file(sys_dirent->d_name); > - if (!dir_path) > - continue; > - evt_dir = opendir(dir_path); > - if (!evt_dir) > - goto next; > - > - for_each_event(dir_path, evt_dir, evt_dirent) { > - snprintf(evt_path, MAXPATHLEN, "%s:%s", > - sys_dirent->d_name, evt_dirent->d_name); > - if (!strcmp(evt_path, event_string)) { > - closedir(evt_dir); > - put_events_file(dir_path); > - closedir(sys_dir); > - return 1; > - } > - } > - closedir(evt_dir); > -next: > - put_events_file(dir_path); > + if (!path) { > + /* Conservatively return false if memory allocation failed. */ > + return false; > } > - closedir(sys_dir); > - return 0; > + /* Copy event_string replacing the ':' with '/'. */ > + for (src = event_string, dst = path; *src; src++, dst++) > + *dst = (*src == ':') ? '/' : *src; > + /* Add "/id\0". */ > + memcpy(dst, "/id", 4); > + > + dst = get_events_file(path); > + if (dst) > + have_file = file_available(dst); If dst == NULL have_file isn't initialized? > + free(dst); > + free(path); > + return have_file; > } > diff --git a/tools/perf/util/tracepoint.h b/tools/perf/util/tracepoint.h > index c4a110fe87d7..65ccb01fc312 100644 > --- a/tools/perf/util/tracepoint.h > +++ b/tools/perf/util/tracepoint.h > @@ -4,6 +4,7 @@ > > #include > #include > +#include > > int tp_event_has_id(const char *dir_path, struct dirent *evt_dir); > > @@ -20,6 +21,6 @@ int tp_event_has_id(const char *dir_path, struct dirent *evt_dir); > (strcmp(sys_dirent->d_name, ".")) && \ > (strcmp(sys_dirent->d_name, ".."))) > > -int is_valid_tracepoint(const char *event_string); > +bool is_valid_tracepoint(const char *event_string); > > #endif /* __PERF_TRACEPOINT_H */ > -- > 2.45.0.rc1.225.g2a3ae87e7f-goog