Commit Graph

11 Commits

Author SHA1 Message Date
Tomas Glozar 083d29d378 rtla/utils: Add idle state disabling via libcpupower
Add functions to utils.c to disable idle states through functions of
libcpupower. This will serve as the basis for disabling idle states
per cpu when running timerlat.

Link: https://lore.kernel.org/20241017140914.3200454-4-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-17 17:13:15 -04:00
Jan Stancek 0eecee3406 tools/rtla: fix collision with glibc sched_attr/sched_set_attr
glibc commit 21571ca0d703 ("Linux: Add the sched_setattr
and sched_getattr functions") now also provides 'struct sched_attr'
and sched_setattr() which collide with the ones from rtla.

  In file included from src/trace.c:11:
  src/utils.h:49:8: error: redefinition of ‘struct sched_attr’
     49 | struct sched_attr {
        |        ^~~~~~~~~~
  In file included from /usr/include/bits/sched.h:60,
                   from /usr/include/sched.h:43,
                   from /usr/include/tracefs/tracefs.h:10,
                   from src/trace.c:4:
  /usr/include/linux/sched/types.h:98:8: note: originally defined here
     98 | struct sched_attr {
        |        ^~~~~~~~~~

Define 'struct sched_attr' conditionally, similar to what strace did:
  https://lore.kernel.org/all/20240930222913.3981407-1-raj.khem@gmail.com/
and rename rtla's version of sched_setattr() to avoid collision.

Link: https://lore.kernel.org/8088f66a7a57c1b209cd8ae0ae7c336a7f8c930d.1728572865.git.jstancek@redhat.com
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-10 20:31:48 -04:00
limingming3 14f08c976f tools/rtla: Replace setting prio with nice for SCHED_OTHER
Since the sched_priority for SCHED_OTHER is always 0, it makes no
sence to set it.
Setting nice for SCHED_OTHER seems more meaningful.

Link: https://lkml.kernel.org/r/20240207065142.1753909-1-limingming3@lixiang.com

Cc: stable@vger.kernel.org
Fixes: b1696371d8 ("rtla: Helper functions for rtla")
Signed-off-by: limingming3 <limingming3@lixiang.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
2024-02-12 10:56:36 +01:00
Daniel Bristot de Oliveira cdca4f4e5e rtla/timerlat_top: Add timerlat user-space support
Add the support for running timerlat threads in user-space. In this
mode, enabled with -u/--user-threads, timerlat dispatches user-space
processes that will loop in the timerlat_fd, measuring the overhead
for going to user-space and then returning to the kernel - in addition
to the existing measurements.

Here is one example of the tool's output with -u enabled:

  $ sudo timerlat top -u -d 600 -q
                                       Timer Latency
    0 00:10:01   |          IRQ Timer Latency (us)        |         Thread Timer Latency (us)      |    Ret user Timer Latency (us)
  CPU COUNT      |      cur       min       avg       max |      cur       min       avg       max |      cur       min       avg       max
    0 #600001    |        0         0         0         3 |        2         1         2         9 |        3         2         3        15
    1 #600001    |        0         0         0         2 |        2         1         2        13 |        2         2         3        18
    2 #600001    |        0         0         0        10 |        2         1         2        16 |        3         2         3        20
    3 #600001    |        0         0         0         7 |        2         1         2        10 |        3         2         3        11
    4 #600000    |        0         0         0        16 |        2         1         2        41 |        3         2         3        58
    5 #600000    |        0         0         0         3 |        2         1         2        10 |        3         2         3        13
    6 #600000    |        0         0         0         5 |        2         1         2         7 |        3         2         3        10
    7 #600000    |        0         0         0         1 |        2         1         2         7 |        3         2         3        10

The tuning setup like -p or -C work for the user-space threads as well.

Link: https://lkml.kernel.org/r/758ad2292a0a1d884138d08219e1a0f572d257a2.1686066600.git.bristot@kernel.org

Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-13 16:38:51 -04:00
Daniel Bristot de Oliveira c58a3f8c7f rtla: Automatically move rtla to a house-keeping cpu
When the user sets -c <cpu-list> try to move rtla out of the <cpu-list>,
even without an -H option. This is useful to avoid having rtla
interfering with the workload.

This works by removing <cpu-list> from rtla's current affinity.

If rtla fails to move itself away it is not that of a problem as this
is an automatic measure.

Link: https://lkml.kernel.org/r/c54304d90c777310fb85a3e658d1449173759aab.1686066600.git.bristot@kernel.org

Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-13 16:30:13 -04:00
Daniel Bristot de Oliveira 272ced2556 rtla: Add --house-keeping option
To avoid having rtla interfering with the measurement threads, add an
option for the user to set the CPUs in which rtla should run. For
instance:

  # rtla timerlat top -H 0 -c 1-7

Will place rtla in the CPU 0, while running the measurement threads in
the CPU 1-7.

Link: https://lkml.kernel.org/r/6a6c78a579a96ba8b02ae67ee1e0ba2cb5e03c4a.1686066600.git.bristot@kernel.org

Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Suggested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-13 16:26:03 -04:00
Daniel Bristot de Oliveira a957cbc025 rtla: Add -C cgroup support
The -C option sets a cgroup to the tracer's threads. If the -C option is
passed without arguments, the tracer's thread will inherit rtla's
cgroup. Otherwise, the threads will be placed on the cgroup passed
to the option.

Link: https://lkml.kernel.org/r/cb051477331d292f17c08bf1d66f0e0384bbe5a5.1686066600.git.bristot@kernel.org

Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-13 16:25:13 -04:00
Daniel Bristot de Oliveira 27e348b221 rtla/timerlat: Add auto-analysis core
Currently, timerlat displays a summary of the timerlat tracer results
saving the trace if the system hits a stop condition.

While this represented a huge step forward, the root cause was not
that is accessible to non-expert users.

The auto-analysis fulfill this gap by parsing the trace timerlat runs,
printing an intuitive auto-analysis.

Link: https://lkml.kernel.org/r/1ee073822f6a2cbb33da0c817331d0d4045e837f.1675179318.git.bristot@kernel.org

Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-02-02 10:48:03 -05:00
Daniel Bristot de Oliveira dada03db9b rtla: Remove procps-ng dependency
Daniel Wagner reported to me that readproc.h got deprecated. Also,
while the procps-ng library was available on Fedora, it was not available
on RHEL, which is a piece of evidence that it was not that used.

rtla uses procps-ng only to find the PID of the tracers' workload.

I used the procps-ng library to avoid reinventing the wheel. But in this
case, reinventing the wheel took me less time than the time we already
took trying to work around problems.

Implement a function that reads /proc/ entries, checking if:
	- the entry is a directory
	- the directory name is composed only of digits (PID)
	- the directory contains the comm file
	- the comm file contains a comm that matches the tracers'
	  workload prefix.
	- then return true; otherwise, return false.

And use it instead of procps-ng.

Link: https://lkml.kernel.org/r/e8276e122ee9eb2c5a0ba8e673fb6488b924b825.1652423574.git.bristot@kernel.org

Cc: John Kacur <jkacur@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tao Zhou <tao.zhou@linux.dev>
Fixes: b1696371d8 ("rtla: Helper functions for rtla")
Reported-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-05-26 15:20:46 -04:00
Daniel Bristot de Oliveira 7d0dc9576d rtla/timerlat: Add --dma-latency option
Add the --dma-latency to set /dev/cpu_dma_latency to the
specified value, this aims to avoid having exit from idle
states latencies that could be influencing the analysis.

Link: https://lkml.kernel.org/r/72ddb0d913459f13217086dadafad88a7c46dd28.1646247211.git.bristot@kernel.org

Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15 14:36:50 -04:00
Daniel Bristot de Oliveira b1696371d8 rtla: Helper functions for rtla
This is a set of utils and tracer helper functions. They are used by
rtla mostly to parse config, display data and some trace operations that
are not part of libtracefs (because they are only useful it for this
case).

Link: https://lkml.kernel.org/r/a94c128aba9e6e66d502b7094f2e8c7ac95b12e5.1639158831.git.bristot@kernel.org

Cc: Tao Zhou <tao.zhou@linux.dev>
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>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 17:02:42 -05:00