From: Daniel Bristot de Oliveira <bristot@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Phil Auld <pauld@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Kate Carcia <kcarcia@redhat.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Jonathan Corbet <corbet@lwn.net>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Alexandre Chartre <alexandre.chartre@oracle.com>,
Clark Willaims <williams@redhat.com>,
John Kacur <jkacur@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
linux-doc@vger.kernel.org
Subject: [PATCH V3 3/9] tracing/hwlat: Switch disable_migrate to mode none
Date: Fri, 14 May 2021 22:51:12 +0200 [thread overview]
Message-ID: <4d341b4315013188685941d254ae94416bfa0512.1621024265.git.bristot@redhat.com> (raw)
In-Reply-To: <cover.1621024265.git.bristot@redhat.com>
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.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
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: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
kernel/trace/trace_hwlat.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index 1f5d48830fd6..fecc3752d7da 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -286,7 +286,6 @@ static int get_sample(void)
}
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");
}
/*
@@ -740,7 +738,6 @@ 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;
--
2.26.3
next prev parent reply other threads:[~2021-05-14 20:52 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-14 20:51 [PATCH V3 0/9] hwlat improvements and osnoise/timerlat tracers Daniel Bristot de Oliveira
2021-05-14 20:51 ` [PATCH V3 1/9] tracing/hwlat: Fix Clark's email Daniel Bristot de Oliveira
2021-05-14 20:51 ` [PATCH V3 2/9] tracing/hwlat: Implement the mode config option Daniel Bristot de Oliveira
2021-06-03 20:11 ` Steven Rostedt
2021-05-14 20:51 ` Daniel Bristot de Oliveira [this message]
2021-05-14 20:51 ` [PATCH V3 4/9] tracing/hwlat: Implement the per-cpu mode Daniel Bristot de Oliveira
2021-05-27 11:58 ` Juri Lelli
2021-05-27 12:29 ` Daniel Bristot de Oliveira
2021-06-03 21:17 ` Steven Rostedt
2021-06-04 15:31 ` Daniel Bristot de Oliveira
2021-05-14 20:51 ` [PATCH V3 5/9] tracing/trace: Add a generic function to read/write u64 values from tracefs Daniel Bristot de Oliveira
2021-06-03 21:22 ` Steven Rostedt
2021-06-04 16:05 ` Daniel Bristot de Oliveira
2021-06-04 16:18 ` Steven Rostedt
2021-06-04 16:34 ` Daniel Bristot de Oliveira
2021-05-14 20:51 ` [PATCH V3 6/9] trace/hwlat: Use the generic function to read/write width and window Daniel Bristot de Oliveira
2021-06-03 21:27 ` Steven Rostedt
2021-06-04 16:36 ` Daniel Bristot de Oliveira
2021-06-04 20:50 ` Steven Rostedt
2021-05-14 20:51 ` [PATCH V3 7/9] tracing: Add __print_ns_to_secs() and __print_ns_without_secs() helpers Daniel Bristot de Oliveira
2021-06-03 21:29 ` Steven Rostedt
2021-06-04 4:19 ` Joe Perches
2021-06-04 16:21 ` Steven Rostedt
2021-06-04 19:09 ` [PATCH] treewide: Add missing semicolons to __assign_str uses Joe Perches
2021-06-04 19:38 ` Joe Perches
2021-06-07 23:18 ` Jason Gunthorpe
2021-06-12 15:42 ` [PATCH V2] " Joe Perches
2021-06-12 23:11 ` Steven Rostedt
2021-06-30 11:28 ` Joe Perches
2021-06-30 12:22 ` Steven Rostedt
2021-06-04 16:07 ` [PATCH V3 7/9] tracing: Add __print_ns_to_secs() and __print_ns_without_secs() helpers Daniel Bristot de Oliveira
2021-05-14 20:51 ` [PATCH V3 8/9] tracing: Add osnoise tracer Daniel Bristot de Oliveira
2021-06-03 21:31 ` Steven Rostedt
2021-06-04 21:28 ` Steven Rostedt
2021-06-07 12:00 ` Daniel Bristot de Oliveira
2021-06-07 15:47 ` Steven Rostedt
2021-06-08 15:24 ` Daniel Bristot de Oliveira
2021-06-08 17:17 ` Daniel Bristot de Oliveira
2021-06-08 17:39 ` Steven Rostedt
2021-06-08 19:33 ` Daniel Bristot de Oliveira
2021-06-08 19:42 ` Steven Rostedt
2021-06-09 12:14 ` Daniel Bristot de Oliveira
2021-06-09 13:03 ` Steven Rostedt
2021-06-09 13:44 ` Daniel Bristot de Oliveira
2021-05-14 20:51 ` [PATCH V3 9/9] tracing: Add timerlat tracer Daniel Bristot de Oliveira
2021-06-08 1:36 ` Steven Rostedt
2021-06-11 12:59 ` Daniel Bristot de Oliveira
2021-06-11 20:03 ` Steven Rostedt
2021-06-12 9:41 ` Daniel Bristot de Oliveira
2021-06-12 23:06 ` Steven Rostedt
2021-06-11 14:13 ` Daniel Bristot de Oliveira
2021-06-11 20:48 ` Steven Rostedt
2021-06-12 8:47 ` Daniel Bristot de Oliveira
2021-06-12 23:09 ` Steven Rostedt
2021-06-15 8:18 ` Daniel Bristot de Oliveira
2021-05-27 12:07 ` [PATCH V3 0/9] hwlat improvements and osnoise/timerlat tracers Juri Lelli
2021-05-29 2:16 ` Steven Rostedt
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=4d341b4315013188685941d254ae94416bfa0512.1621024265.git.bristot@redhat.com \
--to=bristot@redhat.com \
--cc=alexandre.chartre@oracle.com \
--cc=bigeasy@linutronix.de \
--cc=corbet@lwn.net \
--cc=jkacur@redhat.com \
--cc=juri.lelli@redhat.com \
--cc=kcarcia@redhat.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=pauld@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=williams@redhat.com \
/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).