diff options
| author | Daniel Bristot de Oliveira <bristot@redhat.com> | 2021-06-22 16:42:21 +0200 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-06-24 15:37:56 -0400 |
| commit | 7bb7d802af1d0b2608ef5afafcf968073a50acb7 (patch) | |
| tree | 66dacac70ddcf02ce298905b23a7ea1c55765819 /kernel/trace/trace_hwlat.c | |
| parent | 8fa826b7344d6752f5cfd72380d9fe7bd8c6b928 (diff) | |
trace/hwlat: Switch disable_migrate to mode none
When in the round-robin mode, if the tracer detects a change in the
hwlatd thread affinity by an external tool, e.g., taskset, the
round-robin logic is disabled. The disable_migrate variable currently
tracks this.
With the addition of the "mode" config and the mode "none," the
disable_migrate logic is equivalent to switch to the "none" mode.
Hence, instead of using a hidden variable to track this behavior,
switch the mode to none, informing the user about this change.
Link: https://lkml.kernel.org/r/a679af672458d6b1f62252605905c5214030f247.1624372313.git.bristot@redhat.com
Cc: Phil Auld <pauld@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Kate Carcia <kcarcia@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexandre Chartre <alexandre.chartre@oracle.com>
Cc: Clark Willaims <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_hwlat.c')
| -rw-r--r-- | kernel/trace/trace_hwlat.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c index 43a436d85a01..bae74b95cf55 100644 --- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -286,7 +286,6 @@ out: } static struct cpumask save_cpumask; -static bool disable_migrate; static void move_to_next_cpu(void) { @@ -294,15 +293,13 @@ static void move_to_next_cpu(void) struct trace_array *tr = hwlat_trace; int next_cpu; - if (disable_migrate) - return; /* * If for some reason the user modifies the CPU affinity * of this thread, then stop migrating for the duration * of the current test. */ if (!cpumask_equal(current_mask, current->cpus_ptr)) - goto disable; + goto change_mode; get_online_cpus(); cpumask_and(current_mask, cpu_online_mask, tr->tracing_cpumask); @@ -313,7 +310,7 @@ static void move_to_next_cpu(void) next_cpu = cpumask_first(current_mask); if (next_cpu >= nr_cpu_ids) /* Shouldn't happen! */ - goto disable; + goto change_mode; cpumask_clear(current_mask); cpumask_set_cpu(next_cpu, current_mask); @@ -321,8 +318,9 @@ static void move_to_next_cpu(void) sched_setaffinity(0, current_mask); return; - disable: - disable_migrate = true; + change_mode: + hwlat_data.thread_mode = MODE_NONE; + pr_info(BANNER "cpumask changed while in round-robin mode, switching to mode none\n"); } /* @@ -744,7 +742,6 @@ static int hwlat_tracer_init(struct trace_array *tr) hwlat_trace = tr; - disable_migrate = false; hwlat_data.count = 0; tr->max_latency = 0; save_tracing_thresh = tracing_thresh; |