linux-stable.git/tools/tracing/rtla/src/timerlat_hist.c, branch linux-5.17.y

rtla/hist: Make -E the short version of --entries

2022-02-26T02:05:30+00:00

Currently, --entries uses -e as the short version in the hist mode of
timerlat and osnoise tools. But as -e is already used to enable events
on trace sessions by other tools, thus let's keep it available for the
same usage for all rtla tools.

Make -E the short version of --entries for hist mode on all tools.

Note: rtla was merged in this merge window, so rtla was not released yet.

Link: https://lkml.kernel.org/r/5dbf0cbe7364d3a05e708926b41a097c59a02b1e.1645206561.git.bristot@kernel.org

Cc: Jonathan Corbet 
Signed-off-by: Daniel Bristot de Oliveira 
Signed-off-by: Steven Rostedt (Google)

rtla: Fix segmentation fault when failing to enable -t

2022-02-08T16:23:09+00:00

rtla osnoise and timerlat are causing a segmentation fault when running
with the --trace option on a kernel that does not support multiple
instances. For example:

    [root@f34 rtla]# rtla osnoise top -t
    failed to enable the tracer osnoise
    Could not enable osnoiser tracer for tracing
    Failed to enable the trace instance
    Segmentation fault (core dumped)

This error happens because the exit code of the tools is trying
to destroy the trace instance that failed to be created.

Make osnoise_destroy_tool() aware of possible NULL osnoise_tool *,
and do not attempt to destroy it. This also simplifies the exit code.

Link: https://lkml.kernel.org/r/5660a2b6bf66c2655842360f2d7f6b48db5dba23.1644327249.git.bristot@kernel.org

Suggested-by: Steven Rostedt 
Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode")
Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode")
Fixes: a828cd18bc4a ("rtla: Add timerlat tool and timelart top mode")
Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode")
Signed-off-by: Daniel Bristot de Oliveira 
Signed-off-by: Steven Rostedt (Google)

rtla/timerlat: Add timerlat hist mode

2022-01-13T22:02:43+00:00

The rtla hist hist mode displays a histogram of each tracer event
occurrence, both for IRQ and timer latencies. The tool also allows
many configurations of the timerlat tracer and the collection of
the tracer output.

Here is one example of the rtla timerlat hist mode output:
  ---------- %< ----------
 [root@alien ~]# rtla timerlat hist -c 0-3 -d 1M
 # RTLA timerlat histogram
 # Time unit is microseconds (us)
 # Duration:   0 00:01:00
 Index   IRQ-000   Thr-000   IRQ-001   Thr-001   IRQ-002   Thr-002   IRQ-003   Thr-003
 0         58572         0     59373         0     58691         0     58895         0
 1          1422     57021       628     57241      1310     56160      1102     56805
 2             6      2931         0      2695         0      3567         4      3031
 3             1        40         0        53         0       260         0       142
 4             0         7         0         5         0         6         0        17
 5             0         2         0         5         0         7         0         4
 6             0         0         0         2         0         1         0         1
 8             0         0         0         0         0         0         0         1
 over:         0         0         0         0         0         0         0         0
 count:    60001     60001     60001     60001     60001     60001     60001     60001
 min:          0         1         0         1         0         1         0         1
 avg:          0         1         0         1         0         1         0         1
 max:          3         5         1         6         1         6         2         8
  ---------- >% ----------

Running
 - rtla timerlat hist --help
provides information about the available options.

Link: https://lkml.kernel.org/r/7049ed3c46b7d6aceab18ffe7770003dfc4ddceb.1639158831.git.bristot@kernel.org

Cc: Tao Zhou 
Cc: Ingo Molnar 
Cc: Tom Zanussi 
Cc: Masami Hiramatsu 
Cc: Juri Lelli 
Cc: Clark Williams 
Cc: John Kacur 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Sebastian Andrzej Siewior 
Cc: Daniel Bristot de Oliveira 
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 
Signed-off-by: Steven Rostedt