From: Steven Rostedt <rostedt@goodmis.org>
To: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Cc: linux-trace-devel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] trace-cmd: Reset CPU mask to its default value with "trace-cmd reset".
Date: Tue, 1 Oct 2019 11:32:32 -0400 [thread overview]
Message-ID: <20191001113232.644fa2f0@gandalf.local.home> (raw)
In-Reply-To: <20191001145740.8866-3-tz.stoyanov@gmail.com>
On Tue, 1 Oct 2019 17:57:40 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
> "trace-cmd reset" command should put all ftrace config to its default
> state, but trace cpumask was not reseted. The patch sets cpumask to
> its default value - all CPUs are enabled for tracing.
>
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> ---
> tracecmd/trace-record.c | 35 +++++++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
> index 69de82a..6f3520c 100644
> --- a/tracecmd/trace-record.c
> +++ b/tracecmd/trace-record.c
> @@ -4096,6 +4096,40 @@ static void reset_clock(void)
> write_instance_file(instance, "trace_clock", "local", "clock");
> }
>
> +static void reset_cpu_mask(void)
> +{
> + struct buffer_instance *instance;
> + int cpus = count_cpus();
> + int fullwords;
> + char *buf;
> + int bits;
> + int len;
> +
> + fullwords = cpus / 32;
> + bits = cpus % 32;
> + len = (fullwords + 1) * 9;
> +
> + buf = malloc(len + 1);
> + if (!buf) {
> + warning("Unable to allocate %d bytes for cpu mask", len + 1);
> + return;
> + }
> + buf[0] = '\0';
> + if (bits) {
> + sprintf(buf, "%x", (1 << bits) - 1);
> + } else if (fullwords) {
> + strcat(buf, "ffffffff");
> + fullwords--;
> + }
> + while (fullwords-- > 0)
> + strcat(buf, ",ffffffff");
I like my way because it's a little more condensed ;-)
But this works too and it's far from a fast path. As it's probably
more readable, I'll all this one.
-- Steve
> +
> + for_all_instances(instance)
> + write_instance_file(instance, "tracing_cpumask", buf, "cpumask");
> +
> + free(buf);
> +}
> +
> static void reset_event_pid(void)
> {
> add_event_pid("");
> @@ -4808,6 +4842,7 @@ void trace_reset(int argc, char **argv)
> reset_clock();
> reset_event_pid();
> reset_max_latency_instance();
> + reset_cpu_mask();
> tracecmd_remove_instances();
> clear_func_filters();
> /* restore tracing_on to 1 */
next prev parent reply other threads:[~2019-10-01 15:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-01 14:57 [PATCH v2 0/2] Reset CPU mask Tzvetomir Stoyanov (VMware)
2019-10-01 14:57 ` [PATCH v2 1/2] trace-cmd: Reset CPU mask after setting it in trace-cmd record with option -M Tzvetomir Stoyanov (VMware)
2019-10-01 14:57 ` [PATCH v2 2/2] trace-cmd: Reset CPU mask to its default value with "trace-cmd reset" Tzvetomir Stoyanov (VMware)
2019-10-01 15:32 ` Steven Rostedt [this message]
2019-10-01 15:37 ` Tzvetomir Stoyanov
2019-10-01 15:45 ` Steven Rostedt
2019-10-03 14:44 ` [PATCH v2 3/2] trace-cmd: Optimize the logic of reset_cpu_mask() Steven Rostedt
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