From: Daniel Bristot de Oliveira <bristot@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>,
Ingo Molnar <mingo@redhat.com>, Tom Zanussi <zanussi@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Juri Lelli <juri.lelli@redhat.com>,
Clark Williams <williams@redhat.com>,
John Kacur <jkacur@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
linux-rt-users@vger.kernel.org,
linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH V8 1/9] tracing/osnoise: Do not follow tracing_cpumask
Date: Fri, 29 Oct 2021 21:00:27 +0200 [thread overview]
Message-ID: <51293fbd73e6cac131f0ce6914b62a2f9c4ee746.1635533292.git.bristot@kernel.org> (raw)
In-Reply-To: <cover.1635533292.git.bristot@kernel.org>
In preparation to support multiple instances, decouple the
osnoise/timelat workload from instance-specific tracing_cpumask.
Different instances can have conflicting cpumasks, making osnoise
workload management needlessly complex. Osnoise already has its
global cpumask.
I also thought about using the first instance mask, but the
"first" instance could be removed before the others.
This also fixes the problem that changing the tracing_mask was not
re-starting the trace.
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: linux-rt-users@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
---
kernel/trace/trace_osnoise.c | 24 ++++++------------------
1 file changed, 6 insertions(+), 18 deletions(-)
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index ce053619f289..73f9609cba3d 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -1553,13 +1553,9 @@ static int start_per_cpu_kthreads(struct trace_array *tr)
cpus_read_lock();
/*
- * Run only on CPUs in which trace and osnoise are allowed to run.
+ * Run only on online CPUs in which osnoise is allowed to run.
*/
- cpumask_and(current_mask, tr->tracing_cpumask, &osnoise_cpumask);
- /*
- * And the CPU is online.
- */
- cpumask_and(current_mask, cpu_online_mask, current_mask);
+ cpumask_and(current_mask, cpu_online_mask, &osnoise_cpumask);
for_each_possible_cpu(cpu)
per_cpu(per_cpu_osnoise_var, cpu).kthread = NULL;
@@ -1580,10 +1576,8 @@ static int start_per_cpu_kthreads(struct trace_array *tr)
#ifdef CONFIG_HOTPLUG_CPU
static void osnoise_hotplug_workfn(struct work_struct *dummy)
{
- struct trace_array *tr = osnoise_trace;
unsigned int cpu = smp_processor_id();
-
mutex_lock(&trace_types_lock);
if (!osnoise_busy)
@@ -1595,9 +1589,6 @@ static void osnoise_hotplug_workfn(struct work_struct *dummy)
if (!cpumask_test_cpu(cpu, &osnoise_cpumask))
goto out_unlock;
- if (!cpumask_test_cpu(cpu, tr->tracing_cpumask))
- goto out_unlock;
-
start_kthread(cpu);
out_unlock:
@@ -1700,13 +1691,10 @@ static void osnoise_tracer_stop(struct trace_array *tr);
* interface to the osnoise trace. By default, it lists all CPUs,
* in this way, allowing osnoise threads to run on any online CPU
* of the system. It serves to restrict the execution of osnoise to the
- * set of CPUs writing via this interface. Note that osnoise also
- * respects the "tracing_cpumask." Hence, osnoise threads will run only
- * on the set of CPUs allowed here AND on "tracing_cpumask." Why not
- * have just "tracing_cpumask?" Because the user might be interested
- * in tracing what is running on other CPUs. For instance, one might
- * run osnoise in one HT CPU while observing what is running on the
- * sibling HT CPU.
+ * set of CPUs writing via this interface. Why not use "tracing_cpumask"?
+ * Because the user might be interested in tracing what is running on
+ * other CPUs. For instance, one might run osnoise in one HT CPU
+ * while observing what is running on the sibling HT CPU.
*/
static ssize_t
osnoise_cpus_write(struct file *filp, const char __user *ubuf, size_t count,
--
2.31.1
next prev parent reply other threads:[~2021-10-29 19:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-29 19:00 [PATCH V8 0/9] tracing/osnoise: Support multiple instances (for RTLA) Daniel Bristot de Oliveira
2021-10-29 19:00 ` Daniel Bristot de Oliveira [this message]
2021-10-29 19:00 ` [PATCH V8 2/9] tracing/osnoise: Improve comments about barrier need for NMI callbacks Daniel Bristot de Oliveira
2021-10-29 19:00 ` [PATCH V8 3/9] tracing/osnoise: Split workload start from the tracer start Daniel Bristot de Oliveira
2021-10-29 19:00 ` [PATCH V8 4/9] tracing/osnoise: Use start/stop_per_cpu_kthreads() on osnoise_cpus_write() Daniel Bristot de Oliveira
2021-10-29 19:00 ` [PATCH V8 5/9] tracing/osnoise: Support a list of trace_array *tr Daniel Bristot de Oliveira
2021-10-29 19:00 ` [PATCH V8 6/9] tracing/osnoise: Remove TIMERLAT ifdefs from inside functions Daniel Bristot de Oliveira
2021-10-29 19:00 ` [PATCH V8 7/9] tracing/osnoise: Allow multiple instances of the same tracer Daniel Bristot de Oliveira
2021-10-29 19:00 ` [PATCH V8 8/9] tracing/osnoise: Remove STACKTRACE ifdefs from inside functions Daniel Bristot de Oliveira
2021-10-29 19:00 ` [PATCH V8 9/9] tracing/osnoise: Remove PREEMPT_RT " Daniel Bristot de Oliveira
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=51293fbd73e6cac131f0ce6914b62a2f9c4ee746.1635533292.git.bristot@kernel.org \
--to=bristot@kernel.org \
--cc=bigeasy@linutronix.de \
--cc=jkacur@redhat.com \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=linux-trace-devel@vger.kernel.org \
--cc=mhiramat@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=williams@redhat.com \
--cc=zanussi@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).