From: Daniel Bristot de Oliveira <bristot@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Jonathan Corbet <corbet@lwn.net>,
Kate Carcia <kcarcia@redhat.com>,
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>,
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: [RFC 01/19] trace/osnoise: Do not follow tracing_cpumask
Date: Fri, 17 Sep 2021 17:43:44 +0200 [thread overview]
Message-ID: <a65bca17d12a14fb8e6edc241b1390a5edc88cea.1631889858.git.bristot@kernel.org> (raw)
In-Reply-To: <cover.1631889858.git.bristot@kernel.org>
In preparation to support multiple instances, decople the
osnoise/timelat workload from instance specific tracing_cpumask.
Different instances can have conflicing cpumasks, making osnoise
workload management needlessly complex. Osnoise already have its
global cpu mask.
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: 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 | 25 +++++++------------------
1 file changed, 7 insertions(+), 18 deletions(-)
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index ce053619f289..7b1f8187764c 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -1553,13 +1553,10 @@ 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 trace and osnoise are 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 +1577,8 @@ 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 +1590,6 @@ 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 +1692,10 @@ 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:[~2021-09-17 15:45 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-17 15:43 [RFC 00/19] RTLA: An interface for osnoise/timerlat tracers Daniel Bristot de Oliveira
2021-09-17 15:43 ` Daniel Bristot de Oliveira [this message]
2021-09-17 15:43 ` [RFC 02/19] trace/osnoise: Split workload start from the tracer start Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 03/19] trace/osnoise: Use start/stop_per_cpu_kthreads() on osnoise_cpus_write() Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 04/19] trace/osnoise: Support a list of trace_array *tr Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 05/19] trace/osnoise: Allow multiple instances of the same tracer Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 06/19] rtla: Real-Time Linux Analysis tool Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 07/19] rtla: Helper functions for rtla Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 08/19] rtla: Add osnoise tool Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 09/19] rtla/osnoise: Add osnoise top mode Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 10/19] rtla/osnoise: Add the hist mode Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 11/19] rtla: Add timerlat tool and timelart top mode Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 12/19] rtla/timerlat: Add timerlat hist mode Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 13/19] rtla: Add Documentation Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 14/19] rtla: Add rtla osnoise man page Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 15/19] rtla: Add rtla osnoise top documentation Daniel Bristot de Oliveira
2021-09-17 15:43 ` [RFC 16/19] rtla: Add rtla osnoise hist documentation Daniel Bristot de Oliveira
2021-09-17 15:44 ` [RFC 17/19] rtla: Add rtla timerlat documentation Daniel Bristot de Oliveira
2021-09-17 15:44 ` [RFC 18/19] rtla: Add rtla timerlat top documentation Daniel Bristot de Oliveira
2021-09-17 15:44 ` [RFC 19/19] rtla: Add rtla timerlat hist documentation Daniel Bristot de Oliveira
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