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 166E2282F1; Fri, 16 May 2025 19:10:00 +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=1747422601; cv=none; b=ngCvsl5F2kVhkE/J6rUoekguT+ZaakxrqLdlm0muTShGsAljnG4XUgsmfqhkUHmCZ/bkmvOYyvzeqJhtCXv0pkZcz/rFLSfOrsJjasjO5xo7qBJexw8uVjUYmF1QFD3dM3qGpDSp3yndW9crLzEE8+mPKYUmSPVP0e/R9a35kz0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747422601; c=relaxed/simple; bh=T9pQlklBqEb3dr3bCWujpWdBMx+KwCjwxio6EbFWcu0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=T0Jv7CJiTtvKBHYw6HUHMg2rGTKIPOAKM2xDR2uX27ZIwZ5/bcbVgmCSaELauV/C6qTMwcxjZPIVZS0m8LBxYQjTyCqJOgCIBSMYKdtRao0aX/nm4GQLzB5pKy6oMJ/jIg2nDNQS5q/AJ6zz9Fsr2Eo7iG85HBfw3PXpKcYSTeM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=P79X9h6e; 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="P79X9h6e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 00429C4CEE4; Fri, 16 May 2025 19:09:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747422600; bh=T9pQlklBqEb3dr3bCWujpWdBMx+KwCjwxio6EbFWcu0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=P79X9h6ewzj1agY3zPSvYA+BsoQl7SgFxBjr7it9X6I+bs2GLwkbyeSZi3Bmf45GA NTNUqV6fuDZEO1tIEuKBmiwwHYLkhBemJCpQU9ZdMV5pV9ST+tRaLOQaoYgVEJWwEm HbyGA3qQmOiwQpBeSR5pVqnXN/L3MossIUzX4y0b8iEf2lgbUcvKC0VhkeSWu9wjZ9 Atq4njOrxMIBlH1ofcA2IkirwcHJ/tv23j7cuwz13ixVe2uDHpoJpAcBAtySPkLAX/ PQxm/ZXV7uH5pOTsYG/2/Zu4CGiRfmJJLt6donxK4jlNj1HZLfdyLo10ulgvdQYm41 P72QFckfDvumg== Date: Fri, 16 May 2025 16:09:57 -0300 From: Arnaldo Carvalho de Melo To: Thomas Richter Cc: linux390-list@tuxmaker.boeblingen.de.ibm.com, sumanthk@linux.ibm.com, hca@linux.ibm.com, agordeev@linux.ibm.com, gor@linux.ibm.com, Alexander Egorenkov , Steven Rostedt , linux-perf-users@vger.kernel.org, Linux Kernel Mailing List Subject: Re: [PATCH] perf ftrace: Use process/session specific trace settings Message-ID: References: <20250516131023.357458-1-tmricht@linux.ibm.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: CCing Steven, On Fri, May 16, 2025 at 03:52:38PM -0300, Arnaldo Carvalho de Melo wrote: > On Fri, May 16, 2025 at 03:10:23PM +0200, Thomas Richter wrote: > > Executing perf ftrace commands ftrace, profile and latency > > leave tracing disabled as can seen in this output: > > You forgot to CC lkml and linux-perf-users mailing list, I'm doing it > now, noticed when b4 didn't manage to find it. > > Thanks for working on this! From a quick glance it looks great, I'm > testing it now. So, you create the instance, configure it, and at the end you do a rmdir that will trow it away, since we don't need it anymore, but then you're writing to its tunables right before trowing it away, i.e. restoring previous values? I think you can remove that when using instances, right? For instance, at the start you do: openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-gWVKWs/tracing_on", O_WRONLY|O_TRUNC) = 4 write(4, "1\n", 2) And then at the end: openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-gWVKWs/tracing_on", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) Is that a requirement for "tracing_on", could we do away with that, i.e. a rmdir would implicitely stop tracing on that instance? Lemme check: root@number:~# mkdir /sys/kernel/tracing/instances/perf-ftrace-LX75Yk root@number:~# echo function_graph > /sys/kernel/tracing/instances/perf-ftrace-LX75Yk/current_tracer root@number:~# head -5 /sys/kernel/tracing/instances/perf-ftrace-LX75Yk/trace # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 6) 1.924 us | } /* enqueue_entity */ root@number:~# head -10 /sys/kernel/tracing/instances/perf-ftrace-LX75Yk/trace # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 18) 0.140 us | } /* get_nohz_timer_target */ 18) 0.060 us | enqueue_hrtimer(); 18) 0.041 us | _raw_spin_unlock_irqrestore(); 18) 0.632 us | } /* hrtimer_start_range_ns */ 18) 0.802 us | } /* task_non_contending */ 18) | hrtimer_try_to_cancel() { root@number:~# head -10 /sys/kernel/tracing/instances/perf-ftrace-LX75Yk/trace # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 17) 0.090 us | __update_load_avg_se(); 17) 0.051 us | __update_load_avg_cfs_rq(); 17) | update_cfs_group() { 17) 0.050 us | reweight_entity(); 17) 0.260 us | } 17) | place_entity() { root@number:~# rmdir /sys/kernel/tracing/instances/perf-ftrace-LX75Yk root@number:~# ls -la /sys/kernel/tracing/instances/perf-ftrace-LX75Yk ls: cannot access '/sys/kernel/tracing/instances/perf-ftrace-LX75Yk': No such file or directory root@number:~# Yeah, you can just call rmdir and be done with it :-) - Arnaldo mkdir("/sys/kernel/tracing/instances/perf-ftrace-LX75Yk", 0700) = 0 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/tracing_on", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/current_tracer", O_WRONLY|O_TRUNC) = 3 write(3, "nop\n", 4) = 4 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/set_ftrace_pid", O_WRONLY|O_TRUNC) = 3 write(3, " \n", 2) = 2 openat(AT_FDCWD, "/sys/devices/system/cpu/online", O_RDONLY) = 3 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/tracing_cpumask", O_WRONLY|O_TRUNC) = 3 write(3, "ffffffff\n", 9) = 9 openat(AT_FDCWD, "/sys/kernel/tracing/max_graph_depth", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/tracing_thresh", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/set_ftrace_filter", O_WRONLY|O_TRUNC) = 3 write(3, " \n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/set_ftrace_notrace", O_WRONLY|O_TRUNC) = 3 write(3, " \n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/set_graph_function", O_WRONLY|O_TRUNC) = 3 write(3, " \n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/set_graph_notrace", O_WRONLY|O_TRUNC) = 3 write(3, " \n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/function-fork", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/func_stack_trace", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/sleep-time", O_WRONLY|O_TRUNC) = 3 write(3, "1\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/funcgraph-irqs", O_WRONLY|O_TRUNC) = 3 write(3, "1\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/funcgraph-proc", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/funcgraph-abstime", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/funcgraph-tail", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/latency-format", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/irq-info", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/trace", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/set_ftrace_pid", O_WRONLY|O_APPEND) = 3 write(3, "1277499\n", 8) = 8 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/set_ftrace_filter", O_WRONLY|O_APPEND) = 3 write(3, "schedule\n", 9) = 9 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/current_tracer", O_WRONLY|O_TRUNC) = 3 write(3, "function_graph\n", 15) = 15 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/trace_pipe", O_RDONLY) = 3 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/tracing_on", O_WRONLY|O_TRUNC) = 4 write(4, "1\n", 2) = 2 write(6, "\0", 1) = 1 --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=1277499, si_uid=0, si_status=0, si_utime=0, si_stime=0} --- openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/tracing_on", O_WRONLY|O_TRUNC) = 4 write(4, "0\n", 2) = 2 write(1, "# DURATION | COUNT | "..., 81# DURATION | COUNT | GRAPH | ) = 81 write(1, " 0 - 1 us | 0 | "..., 81 0 - 1 us | 0 | | ) = 81 write(1, " 1 - 2 us | 0 | "..., 81 1 - 2 us | 0 | | ) = 81 write(1, " 2 - 4 us | 0 | "..., 81 2 - 4 us | 0 | | ) = 81 write(1, " 4 - 8 us | 0 | "..., 81 4 - 8 us | 0 | | ) = 81 write(1, " 8 - 16 us | 0 | "..., 81 8 - 16 us | 0 | | ) = 81 write(1, " 16 - 32 us | 0 | "..., 81 16 - 32 us | 0 | | ) = 81 write(1, " 32 - 64 us | 0 | "..., 81 32 - 64 us | 0 | | ) = 81 write(1, " 64 - 128 us | 0 | "..., 81 64 - 128 us | 0 | | ) = 81 write(1, " 128 - 256 us | 0 | "..., 81 128 - 256 us | 0 | | ) = 81 write(1, " 256 - 512 us | 0 | "..., 81 256 - 512 us | 0 | | ) = 81 write(1, " 512 - 1024 us | 0 | "..., 81 512 - 1024 us | 0 | | ) = 81 write(1, " 1 - 2 ms | 0 | "..., 81 1 - 2 ms | 0 | | ) = 81 write(1, " 2 - 4 ms | 0 | "..., 81 2 - 4 ms | 0 | | ) = 81 write(1, " 4 - 8 ms | 0 | "..., 81 4 - 8 ms | 0 | | ) = 81 write(1, " 8 - 16 ms | 0 | "..., 81 8 - 16 ms | 0 | | ) = 81 write(1, " 16 - 32 ms | 0 | "..., 81 16 - 32 ms | 0 | | ) = 81 write(1, " 32 - 64 ms | 0 | "..., 81 32 - 64 ms | 0 | | ) = 81 write(1, " 64 - 128 ms | 0 | "..., 81 64 - 128 ms | 0 | | ) = 81 write(1, " 128 - 256 ms | 0 | "..., 81 128 - 256 ms | 0 | | ) = 81 write(1, " 256 - 512 ms | 1 | "..., 81 256 - 512 ms | 1 | ############################################## | ) = 81 write(1, " 512 - 1024 ms | 0 | "..., 81 512 - 1024 ms | 0 | | ) = 81 write(1, " 1 - ... s | 0 | "..., 81 1 - ... s | 0 | | ) = 81 write(1, "\n# statistics (in usec)\n", 25 # statistics (in usec) ) = 25 write(1, " total time: 10000"..., 35 total time: 1000044 ) = 35 write(1, " avg time: 10000"..., 35 avg time: 1000044 ) = 35 write(1, " max time: 10000"..., 35 max time: 1000044 ) = 35 write(1, " min time: 10000"..., 35 min time: 1000044 ) = 35 write(1, " count: "..., 35 count: 1 ) = 35 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/tracing_on", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/current_tracer", O_WRONLY|O_TRUNC) = 3 write(3, "nop\n", 4) = 4 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/set_ftrace_pid", O_WRONLY|O_TRUNC) = 3 write(3, " \n", 2) = 2 openat(AT_FDCWD, "/sys/devices/system/cpu/online", O_RDONLY) = 3 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/tracing_cpumask", O_WRONLY|O_TRUNC) = 3 write(3, "ffffffff\n", 9) = 9 openat(AT_FDCWD, "/sys/kernel/tracing/max_graph_depth", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/tracing_thresh", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/set_ftrace_filter", O_WRONLY|O_TRUNC) = 3 write(3, " \n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/set_ftrace_notrace", O_WRONLY|O_TRUNC) = 3 write(3, " \n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/set_graph_function", O_WRONLY|O_TRUNC) = 3 write(3, " \n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/set_graph_notrace", O_WRONLY|O_TRUNC) = 3 write(3, " \n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/function-fork", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/func_stack_trace", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/sleep-time", O_WRONLY|O_TRUNC) = 3 write(3, "1\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/funcgraph-irqs", O_WRONLY|O_TRUNC) = 3 write(3, "1\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/funcgraph-proc", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/funcgraph-abstime", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/funcgraph-tail", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/latency-format", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 openat(AT_FDCWD, "/sys/kernel/tracing/instances/perf-ftrace-LX75Yk/options/irq-info", O_WRONLY|O_TRUNC) = 3 write(3, "0\n", 2) = 2 rmdir("/sys/kernel/tracing/instances/perf-ftrace-LX75Yk") = 0 +++ exited with 0 +++ root@number:~# > > # echo 1 > /sys/kernel/debug/tracing/tracing_on > > # cat /sys/kernel/debug/tracing/tracing_on > > 1 > > # perf ftrace trace --graph-opts depth=5 sleep 0.1 > /dev/null > > # cat /sys/kernel/debug/tracing/tracing_on > > 0 > > # > > > > The tracing_on file is not restored to its value before the command. > > Fix this behavior and restore the trace setting to what > > is was before the invocation of the command. > > On Fedora 41 and 42 tracing is turned on by default. > > > > This patch use the .../tracing/instances/XXX subdirectory feature. > > Each perf ftrace invocation creates its own session/process > > specific subdirectory and does not change the global state > > in the .../tracing directory itself. > > > > Signed-off-by: Thomas Richter > > Suggested-by: Arnaldo Carvalho de Melo > > Reported-by: Alexander Egorenkov > > --- > > tools/perf/builtin-ftrace.c | 79 ++++++++++++++++++++++++++++++++++--- > > 1 file changed, 73 insertions(+), 6 deletions(-) > > > > diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c > > index 7caa18d5ffc3..f523039c585f 100644 > > --- a/tools/perf/builtin-ftrace.c > > +++ b/tools/perf/builtin-ftrace.c > > @@ -38,6 +38,8 @@ > > #include "util/units.h" > > #include "util/parse-sublevel-options.h" > > > > +#include > > + > > #define DEFAULT_TRACER "function_graph" > > > > static volatile sig_atomic_t workload_exec_errno; > > @@ -45,6 +47,8 @@ static volatile sig_atomic_t done; > > > > static struct stats latency_stats; /* for tracepoints */ > > > > +static char tracing_instance[PATH_MAX]; /* Trace instance directory */ > > + > > static void sig_handler(int sig __maybe_unused) > > { > > done = true; > > @@ -100,6 +104,34 @@ static bool is_ftrace_supported(void) > > return supported; > > } > > > > +/* > > + * Wrapper to test if a file in directory .../tracing/instances/XXX > > + * exists. If so return the .../tracing/instances/XXX file for use. > > + * Otherwise the file exists only in directory .../tracing and > > + * is applicable to all instances, for example file available_filter_functions. > > + * Return that file name in this case. > > + * > > + * This functions works similar to get_tracing_file() and expects its caller > > + * to free the returned file name. > > + * > > + * The global variable tracing_instance is set in init_tracing_instance() > > + * called a the beginning to a process specific tracing subdirectory. > > + */ > > +static char *get_tracing_instance_file(const char *name) > > +{ > > + char *file; > > + > > + if (asprintf(&file, "%s/%s", tracing_instance, name) < 0) > > + return NULL; > > + > > + if (!access(file, F_OK)) > > + return file; > > + > > + put_tracing_file(file); > > + file = get_tracing_file(name); > > + return file; > > +} > > + > > static int __write_tracing_file(const char *name, const char *val, bool append) > > { > > char *file; > > @@ -109,7 +141,7 @@ static int __write_tracing_file(const char *name, const char *val, bool append) > > char errbuf[512]; > > char *val_copy; > > > > - file = get_tracing_file(name); > > + file = get_tracing_instance_file(name); > > if (!file) { > > pr_debug("cannot get tracing file: %s\n", name); > > return -1; > > @@ -167,7 +199,7 @@ static int read_tracing_file_to_stdout(const char *name) > > int fd; > > int ret = -1; > > > > - file = get_tracing_file(name); > > + file = get_tracing_instance_file(name); > > if (!file) { > > pr_debug("cannot get tracing file: %s\n", name); > > return -1; > > @@ -209,7 +241,7 @@ static int read_tracing_file_by_line(const char *name, > > char *file; > > FILE *fp; > > > > - file = get_tracing_file(name); > > + file = get_tracing_instance_file(name); > > if (!file) { > > pr_debug("cannot get tracing file: %s\n", name); > > return -1; > > @@ -299,6 +331,36 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused) > > return 0; > > } > > > > +/* Remove .../tracing/instances/XXX subdirectory created with > > + * init_tracing_instance(). > > + */ > > +static void exit_tracing_instance(void) > > +{ > > + rmdir(tracing_instance); > > +} > > + > > +/* Create subdirectory within .../tracing/instances/XXX to have session > > + * or process specific setup. To delete this setup, simply remove the > > + * subdirectory. > > + */ > > +static int init_tracing_instance(void) > > +{ > > + char dirname[] = "instances/perf-ftrace-XXXXXX"; > > + char *path; > > + > > + path = get_tracing_file(dirname); > > + if (!path) > > + return -1; > > + strcpy(tracing_instance, path); > > + put_tracing_file(path); > > + path = mkdtemp(tracing_instance); > > + if (!path) { > > + pr_err("failed to create tracing/instances directory\n"); > > + return -1; > > + } > > + return 0; > > +} > > + > > static int set_tracing_pid(struct perf_ftrace *ftrace) > > { > > int i; > > @@ -648,7 +710,7 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace) > > > > setup_pager(); > > > > - trace_file = get_tracing_file("trace_pipe"); > > + trace_file = get_tracing_instance_file("trace_pipe"); > > if (!trace_file) { > > pr_err("failed to open trace_pipe\n"); > > goto out_reset; > > @@ -942,7 +1004,7 @@ static int prepare_func_latency(struct perf_ftrace *ftrace) > > return -1; > > } > > > > - trace_file = get_tracing_file("trace_pipe"); > > + trace_file = get_tracing_instance_file("trace_pipe"); > > if (!trace_file) { > > pr_err("failed to open trace_pipe\n"); > > return -1; > > @@ -1323,7 +1385,7 @@ static int __cmd_profile(struct perf_ftrace *ftrace) > > > > setup_pager(); > > > > - trace_file = get_tracing_file("trace_pipe"); > > + trace_file = get_tracing_instance_file("trace_pipe"); > > if (!trace_file) { > > pr_err("failed to open trace_pipe\n"); > > goto out_reset; > > @@ -1740,6 +1802,9 @@ int cmd_ftrace(int argc, const char **argv) > > if (!argc && target__none(&ftrace.target)) > > ftrace.target.system_wide = true; > > > > + if (init_tracing_instance()) > > + goto out_delete_filters; > > + > > switch (subcmd) { > > case PERF_FTRACE_TRACE: > > cmd_func = __cmd_ftrace; > > @@ -1839,5 +1904,7 @@ int cmd_ftrace(int argc, const char **argv) > > delete_filter_func(&ftrace.graph_funcs); > > delete_filter_func(&ftrace.nograph_funcs); > > > > + exit_tracing_instance(); > > + > > return ret; > > } > > -- > > 2.49.0