<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools/tracing/rtla, branch v6.12</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>rtla: Fix the help text in osnoise and timerlat top tools</title>
<updated>2024-10-03T20:43:22+00:00</updated>
<author>
<name>Eder Zulian</name>
<email>ezulian@redhat.com</email>
</author>
<published>2024-08-13T15:58:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3d7b8ea7a8a20a45d019382c4dc6ed79e8bb95cf'/>
<id>3d7b8ea7a8a20a45d019382c4dc6ed79e8bb95cf</id>
<content type='text'>
The help text in osnoise top and timerlat top had some minor errors
and omissions. The -d option was missing the 's' (second) abbreviation and
the error message for '-d' used '-D'.

Cc: stable@vger.kernel.org
Fixes: 1eceb2fc2ca54 ("rtla/osnoise: Add osnoise top mode")
Fixes: a828cd18bc4ad ("rtla: Add timerlat tool and timelart top mode")
Link: https://lore.kernel.org/20240813155831.384446-1-ezulian@redhat.com
Suggested-by: Tomas Glozar &lt;tglozar@redhat.com&gt;
Reviewed-by: Tomas Glozar &lt;tglozar@redhat.com&gt;
Signed-off-by: Eder Zulian &lt;ezulian@redhat.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The help text in osnoise top and timerlat top had some minor errors
and omissions. The -d option was missing the 's' (second) abbreviation and
the error message for '-d' used '-D'.

Cc: stable@vger.kernel.org
Fixes: 1eceb2fc2ca54 ("rtla/osnoise: Add osnoise top mode")
Fixes: a828cd18bc4ad ("rtla: Add timerlat tool and timelart top mode")
Link: https://lore.kernel.org/20240813155831.384446-1-ezulian@redhat.com
Suggested-by: Tomas Glozar &lt;tglozar@redhat.com&gt;
Reviewed-by: Tomas Glozar &lt;tglozar@redhat.com&gt;
Signed-off-by: Eder Zulian &lt;ezulian@redhat.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/rtla: Fix installation from out-of-tree build</title>
<updated>2024-10-03T20:43:22+00:00</updated>
<author>
<name>Ben Hutchings</name>
<email>benh@debian.org</email>
</author>
<published>2024-09-15T23:31:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f771d5369f1dbfe32c93bcb4f5d7ca8322b15389'/>
<id>f771d5369f1dbfe32c93bcb4f5d7ca8322b15389</id>
<content type='text'>
rtla now supports out-of-tree builds, but installation fails as it
still tries to install the rtla binary from the source tree.  Use the
existing macro $(RTLA) to refer to the binary.

Link: https://lore.kernel.org/ZudubuoU_JHjPZ7w@decadent.org.uk
Fixes: 01474dc706ca ("tools/rtla: Use tools/build makefiles to build rtla")
Reviewed-by: Tomas Glozar &lt;tglozar@redhat.com&gt;
Tested-by: Tomas Glozar &lt;tglozar@redhat.com&gt;
Signed-off-by: Ben Hutchings &lt;benh@debian.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
rtla now supports out-of-tree builds, but installation fails as it
still tries to install the rtla binary from the source tree.  Use the
existing macro $(RTLA) to refer to the binary.

Link: https://lore.kernel.org/ZudubuoU_JHjPZ7w@decadent.org.uk
Fixes: 01474dc706ca ("tools/rtla: Use tools/build makefiles to build rtla")
Reviewed-by: Tomas Glozar &lt;tglozar@redhat.com&gt;
Tested-by: Tomas Glozar &lt;tglozar@redhat.com&gt;
Signed-off-by: Ben Hutchings &lt;benh@debian.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtla/osnoise: Prevent NULL dereference in error handling</title>
<updated>2024-08-09T17:03:15+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@linaro.org</email>
</author>
<published>2024-08-09T12:34:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=90574d2a675947858b47008df8d07f75ea50d0d0'/>
<id>90574d2a675947858b47008df8d07f75ea50d0d0</id>
<content type='text'>
If the "tool-&gt;data" allocation fails then there is no need to call
osnoise_free_top() and, in fact, doing so will lead to a NULL dereference.

Cc: stable@vger.kernel.org
Cc: John Kacur &lt;jkacur@redhat.com&gt;
Cc: "Luis Claudio R. Goncalves" &lt;lgoncalv@redhat.com&gt;
Cc: Clark Williams &lt;williams@redhat.com&gt;
Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode")
Link: https://lore.kernel.org/f964ed1f-64d2-4fde-ad3e-708331f8f358@stanley.mountain
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If the "tool-&gt;data" allocation fails then there is no need to call
osnoise_free_top() and, in fact, doing so will lead to a NULL dereference.

Cc: stable@vger.kernel.org
Cc: John Kacur &lt;jkacur@redhat.com&gt;
Cc: "Luis Claudio R. Goncalves" &lt;lgoncalv@redhat.com&gt;
Cc: Clark Williams &lt;williams@redhat.com&gt;
Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode")
Link: https://lore.kernel.org/f964ed1f-64d2-4fde-ad3e-708331f8f358@stanley.mountain
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'perf-tools-fixes-for-v6.11-2024-07-23' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools</title>
<updated>2024-07-24T01:15:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-07-24T01:15:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=786c8248dbd33a5a7a07f7c6e55a7bfc68d2ca48'/>
<id>786c8248dbd33a5a7a07f7c6e55a7bfc68d2ca48</id>
<content type='text'>
Pull perf tools fixes from Namhyung Kim:
 "Two fixes for building perf and other tools:

   - Fix breakage in tracing tools due to pkg-config for
     libtrace{event,fs}

   - Fix build of perf when libunwind is used"

* tag 'perf-tools-fixes-for-v6.11-2024-07-23' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  perf dso: Fix build when libunwind is enabled
  tools/latency: Use pkg-config in lib_setup of Makefile.config
  tools/rtla: Use pkg-config in lib_setup of Makefile.config
  tools/verification: Use pkg-config in lib_setup of Makefile.config
  tools: Make pkg-config dependency checks usable by other tools
  perf build: Warn if libtracefs is not found
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf tools fixes from Namhyung Kim:
 "Two fixes for building perf and other tools:

   - Fix breakage in tracing tools due to pkg-config for
     libtrace{event,fs}

   - Fix build of perf when libunwind is used"

* tag 'perf-tools-fixes-for-v6.11-2024-07-23' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  perf dso: Fix build when libunwind is enabled
  tools/latency: Use pkg-config in lib_setup of Makefile.config
  tools/rtla: Use pkg-config in lib_setup of Makefile.config
  tools/verification: Use pkg-config in lib_setup of Makefile.config
  tools: Make pkg-config dependency checks usable by other tools
  perf build: Warn if libtracefs is not found
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/rtla: Use pkg-config in lib_setup of Makefile.config</title>
<updated>2024-07-17T20:15:08+00:00</updated>
<author>
<name>Guilherme Amadio</name>
<email>amadio@gentoo.org</email>
</author>
<published>2024-07-12T19:40:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eb545a42d0f1da8dd1a09072cff18f5605add05b'/>
<id>eb545a42d0f1da8dd1a09072cff18f5605add05b</id>
<content type='text'>
This allows to build against libtraceevent and libtracefs installed
in non-standard locations.

Signed-off-by: Guilherme Amadio &lt;amadio@gentoo.org&gt;
Tested-by: Thorsten Leemhuis &lt;linux@leemhuis.info&gt;
Tested-by: Leo Yan &lt;leo.yan@arm.com&gt;
Acked-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Link: https://lore.kernel.org/r/20240712194511.3973899-5-amadio@gentoo.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This allows to build against libtraceevent and libtracefs installed
in non-standard locations.

Signed-off-by: Guilherme Amadio &lt;amadio@gentoo.org&gt;
Tested-by: Thorsten Leemhuis &lt;linux@leemhuis.info&gt;
Tested-by: Leo Yan &lt;leo.yan@arm.com&gt;
Acked-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Link: https://lore.kernel.org/r/20240712194511.3973899-5-amadio@gentoo.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtla/osnoise: Better report when histogram is empty</title>
<updated>2024-06-21T08:19:53+00:00</updated>
<author>
<name>Luis Claudio R. Goncalves</name>
<email>lgoncalv@redhat.com</email>
</author>
<published>2024-06-12T10:36:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=587f05a88bd49c0c1f4c1b900787cedef461a902'/>
<id>587f05a88bd49c0c1f4c1b900787cedef461a902</id>
<content type='text'>
When osnoise hist does not observe any samples above the threshold,
no entries are recorded and the final report shows empty entries
for the usual statistics (count, min, max, avg):

    [~]# osnoise hist -d 5s -T 500
    # RTLA osnoise histogram
    # Time unit is microseconds (us)
    # Duration:   0 00:00:05
    Index
    over:
    count:
    min:
    avg:
    max:

That could lead users to confusing interpretations of the results.

A simple solution is to report 0 for count and the statistics, making it
clear that no noise (above the defined threshold) was observed:

    [~]# osnoise hist -d 5s -T 500
    # RTLA osnoise histogram
    # Time unit is microseconds (us)
    # Duration:   0 00:00:05
    Index
    over: 0
    count: 0
    min: 0
    avg: 0
    max: 0

Link: https://lkml.kernel.org/r/Zml6JmH5cbS7-HfZ@uudg.org

Cc: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
Cc: John Kacur &lt;jkacur@redhat.com&gt;
Cc: Clark Williams &lt;williams@redhat.com&gt;
Reviewed-by: John Kacur &lt;jkacur@redhat.com&gt;
Signed-off-by: Luis Claudio R. Goncalves &lt;lgoncalv@redhat.com&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When osnoise hist does not observe any samples above the threshold,
no entries are recorded and the final report shows empty entries
for the usual statistics (count, min, max, avg):

    [~]# osnoise hist -d 5s -T 500
    # RTLA osnoise histogram
    # Time unit is microseconds (us)
    # Duration:   0 00:00:05
    Index
    over:
    count:
    min:
    avg:
    max:

That could lead users to confusing interpretations of the results.

A simple solution is to report 0 for count and the statistics, making it
clear that no noise (above the defined threshold) was observed:

    [~]# osnoise hist -d 5s -T 500
    # RTLA osnoise histogram
    # Time unit is microseconds (us)
    # Duration:   0 00:00:05
    Index
    over: 0
    count: 0
    min: 0
    avg: 0
    max: 0

Link: https://lkml.kernel.org/r/Zml6JmH5cbS7-HfZ@uudg.org

Cc: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
Cc: John Kacur &lt;jkacur@redhat.com&gt;
Cc: Clark Williams &lt;williams@redhat.com&gt;
Reviewed-by: John Kacur &lt;jkacur@redhat.com&gt;
Signed-off-by: Luis Claudio R. Goncalves &lt;lgoncalv@redhat.com&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtla/osnoise: Use pretty formatting only on interactive tty</title>
<updated>2024-06-21T08:17:51+00:00</updated>
<author>
<name>Luis Claudio R. Goncalves</name>
<email>lgoncalv@redhat.com</email>
</author>
<published>2024-06-10T13:25:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=59237b0c962e8a4e03a7666b8c1d047c262f236e'/>
<id>59237b0c962e8a4e03a7666b8c1d047c262f236e</id>
<content type='text'>
osnoise top performs background/font color formatting that could make
the text output confusing if not on a terminal. Use the changes from
commit f5c0cdad6684a ("rtla/timerlat: Use pretty formatting only on
interactive tty") as an inspiration to fix this problem.

Apply the formatting only if running on a tty, and not in quiet mode.

Link: https://lkml.kernel.org/r/Zmb-yP_3EDHliI8Z@uudg.org

Suggested-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
Reviewed-by: John Kacur &lt;jkacur@redhat.com&gt;
Reviewed-by: Clark Williams &lt;williams@redhat.com&gt;
Signed-off-by: Luis Claudio R. Goncalves &lt;lgoncalv@redhat.com&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
osnoise top performs background/font color formatting that could make
the text output confusing if not on a terminal. Use the changes from
commit f5c0cdad6684a ("rtla/timerlat: Use pretty formatting only on
interactive tty") as an inspiration to fix this problem.

Apply the formatting only if running on a tty, and not in quiet mode.

Link: https://lkml.kernel.org/r/Zmb-yP_3EDHliI8Z@uudg.org

Suggested-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
Reviewed-by: John Kacur &lt;jkacur@redhat.com&gt;
Reviewed-by: Clark Williams &lt;williams@redhat.com&gt;
Signed-off-by: Luis Claudio R. Goncalves &lt;lgoncalv@redhat.com&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtla: Fix -t\--trace[=file]</title>
<updated>2024-05-16T14:49:10+00:00</updated>
<author>
<name>John Kacur</name>
<email>jkacur@redhat.com</email>
</author>
<published>2024-05-15T18:30:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=842fc5b87a5058d475b9411dbb94ed49f8d6bce3'/>
<id>842fc5b87a5058d475b9411dbb94ed49f8d6bce3</id>
<content type='text'>
The -t option has an optional argument.
The usual case is for a short option to be specified without an '='
and for the long version to be specified with an '='

Various forms of this do not work as expected.
For example:
rtla timerlat hist -T50 -tfile.txt
will result in a truncated file name of "ile.txt"

Another example is that the long form without the '=' will result in the
default file name instead of the requested file name.

This patch properly parses the optional argument with and without '='
and with and without spaces for the short form.

This patch was also tested using -t and --trace without providing a file
name both as the last requested option and with a following long and
short option.

For example:

  rtla timerlat hist -T50 -t -u
  rtla timerlat hist -T50 --trace -u

This fix is applied to both timerlat top and hist
and to osnoise top and hist.

Here is the full testing for rtla timerlat hist.
Before applying the patch

  rtla timerlat hist -T50 -t=file.txt
    Works as expected, "file.txt"

  rtla timerlat hist -T50 -tfile.txt
    Truncated file name "ile.txt"

  rtla timerlat hist -T50 -t file.txt
    Default file name instead of file.txt

  rtla timerlat hist -T50 --trace=file.txt
    Truncated file name "ile.txt"

  rtla timerlat hist -T50 --trace file.txt
    Default file name "timerlat_trace.txt" instead of "file.txt"

After applying the patch:

  rtla timerlat hist -T50 -t=file.txt
    Works as expected, "file.txt"

  rtla timerlat hist -T50 -tfile.txt
    Works as expected, "file.txt"

  rtla timerlat hist -T50 -t file.txt
    Works as expected, "file.txt"

  rtla timerlat hist -T50 --trace=file.txt
    Works as expected, "file.txt"

  rtla timerlat hist -T50 --trace file.txt
    Works as expected, "file.txt"

In addition the following tests were performed to make sure that
the default file name worked as expected including with trailing
options.

  rtla timerlat hist -T50 -t
    Works as expected "timerlat_trace.txt"

  rtla timerlat hist -T50 --trace
    Works as expected "timerlat_trace.txt"

  rtla timerlat hist -T50 -t -u
    Works as expected "timerlat_trace.txt"

  rtla timerlat hist -T50 --trace -u
    Works as expected "timerlat_trace.txt"

Link: https://lkml.kernel.org/r/20240515183024.59985-1-jkacur@redhat.com

Cc: Daniel Bristot de Oliveria &lt;bristot@kernel.org&gt;
Signed-off-by: John Kacur &lt;jkacur@redhat.com&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The -t option has an optional argument.
The usual case is for a short option to be specified without an '='
and for the long version to be specified with an '='

Various forms of this do not work as expected.
For example:
rtla timerlat hist -T50 -tfile.txt
will result in a truncated file name of "ile.txt"

Another example is that the long form without the '=' will result in the
default file name instead of the requested file name.

This patch properly parses the optional argument with and without '='
and with and without spaces for the short form.

This patch was also tested using -t and --trace without providing a file
name both as the last requested option and with a following long and
short option.

For example:

  rtla timerlat hist -T50 -t -u
  rtla timerlat hist -T50 --trace -u

This fix is applied to both timerlat top and hist
and to osnoise top and hist.

Here is the full testing for rtla timerlat hist.
Before applying the patch

  rtla timerlat hist -T50 -t=file.txt
    Works as expected, "file.txt"

  rtla timerlat hist -T50 -tfile.txt
    Truncated file name "ile.txt"

  rtla timerlat hist -T50 -t file.txt
    Default file name instead of file.txt

  rtla timerlat hist -T50 --trace=file.txt
    Truncated file name "ile.txt"

  rtla timerlat hist -T50 --trace file.txt
    Default file name "timerlat_trace.txt" instead of "file.txt"

After applying the patch:

  rtla timerlat hist -T50 -t=file.txt
    Works as expected, "file.txt"

  rtla timerlat hist -T50 -tfile.txt
    Works as expected, "file.txt"

  rtla timerlat hist -T50 -t file.txt
    Works as expected, "file.txt"

  rtla timerlat hist -T50 --trace=file.txt
    Works as expected, "file.txt"

  rtla timerlat hist -T50 --trace file.txt
    Works as expected, "file.txt"

In addition the following tests were performed to make sure that
the default file name worked as expected including with trailing
options.

  rtla timerlat hist -T50 -t
    Works as expected "timerlat_trace.txt"

  rtla timerlat hist -T50 --trace
    Works as expected "timerlat_trace.txt"

  rtla timerlat hist -T50 -t -u
    Works as expected "timerlat_trace.txt"

  rtla timerlat hist -T50 --trace -u
    Works as expected "timerlat_trace.txt"

Link: https://lkml.kernel.org/r/20240515183024.59985-1-jkacur@redhat.com

Cc: Daniel Bristot de Oliveria &lt;bristot@kernel.org&gt;
Signed-off-by: John Kacur &lt;jkacur@redhat.com&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtla/timerlat: Fix histogram report when a cpu count is 0</title>
<updated>2024-05-16T14:45:40+00:00</updated>
<author>
<name>John Kacur</name>
<email>jkacur@redhat.com</email>
</author>
<published>2024-05-10T19:03:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=01b05fc0e5f3aec443a9a8ffa0022cbca2fd3608'/>
<id>01b05fc0e5f3aec443a9a8ffa0022cbca2fd3608</id>
<content type='text'>
On short runs it is possible to get no samples on a cpu, like this:

  # rtla timerlat hist -u -T50

  Index   IRQ-001   Thr-001   Usr-001   IRQ-002   Thr-002   Usr-002
  2             1         0         0         0         0         0
  33            0         1         0         0         0         0
  36            0         0         1         0         0         0
  49            0         0         0         1         0         0
  52            0         0         0         0         1         0
  over:         0         0         0         0         0         0
  count:        1         1         1         1         1         0
  min:          2        33        36        49        52 18446744073709551615
  avg:          2        33        36        49        52         -
  max:          2        33        36        49        52         0
  rtla timerlat hit stop tracing
    IRQ handler delay:		(exit from idle)	    48.21 us (91.09 %)
    IRQ latency:						    49.11 us
    Timerlat IRQ duration:				     2.17 us (4.09 %)
    Blocking thread:					     1.01 us (1.90 %)
  	               swapper/2:0        		     1.01 us
  ------------------------------------------------------------------------
    Thread latency:					    52.93 us (100%)

  Max timerlat IRQ latency from idle: 49.11 us in cpu 2

Note, the value 18446744073709551615 is the same as ~0.

Fix this by reporting no results for the min, avg and max if the count
is 0.

Link: https://lkml.kernel.org/r/20240510190318.44295-1-jkacur@redhat.com

Cc: stable@vger.kernel.org
Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode")
Suggested-by: Daniel Bristot de Oliveria &lt;bristot@kernel.org&gt;
Signed-off-by: John Kacur &lt;jkacur@redhat.com&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On short runs it is possible to get no samples on a cpu, like this:

  # rtla timerlat hist -u -T50

  Index   IRQ-001   Thr-001   Usr-001   IRQ-002   Thr-002   Usr-002
  2             1         0         0         0         0         0
  33            0         1         0         0         0         0
  36            0         0         1         0         0         0
  49            0         0         0         1         0         0
  52            0         0         0         0         1         0
  over:         0         0         0         0         0         0
  count:        1         1         1         1         1         0
  min:          2        33        36        49        52 18446744073709551615
  avg:          2        33        36        49        52         -
  max:          2        33        36        49        52         0
  rtla timerlat hit stop tracing
    IRQ handler delay:		(exit from idle)	    48.21 us (91.09 %)
    IRQ latency:						    49.11 us
    Timerlat IRQ duration:				     2.17 us (4.09 %)
    Blocking thread:					     1.01 us (1.90 %)
  	               swapper/2:0        		     1.01 us
  ------------------------------------------------------------------------
    Thread latency:					    52.93 us (100%)

  Max timerlat IRQ latency from idle: 49.11 us in cpu 2

Note, the value 18446744073709551615 is the same as ~0.

Fix this by reporting no results for the min, avg and max if the count
is 0.

Link: https://lkml.kernel.org/r/20240510190318.44295-1-jkacur@redhat.com

Cc: stable@vger.kernel.org
Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode")
Suggested-by: Daniel Bristot de Oliveria &lt;bristot@kernel.org&gt;
Signed-off-by: John Kacur &lt;jkacur@redhat.com&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtla: Add --trace-buffer-size option</title>
<updated>2024-05-16T14:44:34+00:00</updated>
<author>
<name>Daniel Bristot de Oliveira</name>
<email>bristot@kernel.org</email>
</author>
<published>2024-05-16T14:15:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e9a4062e1527238c5649d0f4be794a8566fd77c9'/>
<id>e9a4062e1527238c5649d0f4be794a8566fd77c9</id>
<content type='text'>
Add the option allow the users to set a different buffer size for the
trace. For example, in large systems, the user might be interested on
reducing the trace buffer to avoid large tracing files.

The buffer size is specified in kB, and it is only affecting
the tracing instance.

The function trace_set_buffer_size() appears on libtracefs v1.6,
so increase the minimum required version on Makefile.config.

Link: https://lkml.kernel.org/r/e7c9ca5b3865f28e131a49ec3b984fadf2d056c6.1715860611.git.bristot@kernel.org

Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Juri Lelli &lt;juri.lelli@redhat.com&gt;
Cc: John Kacur &lt;jkacur@redhat.com&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add the option allow the users to set a different buffer size for the
trace. For example, in large systems, the user might be interested on
reducing the trace buffer to avoid large tracing files.

The buffer size is specified in kB, and it is only affecting
the tracing instance.

The function trace_set_buffer_size() appears on libtracefs v1.6,
so increase the minimum required version on Makefile.config.

Link: https://lkml.kernel.org/r/e7c9ca5b3865f28e131a49ec3b984fadf2d056c6.1715860611.git.bristot@kernel.org

Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Juri Lelli &lt;juri.lelli@redhat.com&gt;
Cc: John Kacur &lt;jkacur@redhat.com&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
