linux.git/tools/tracing/rtla/src, branch vsnprintf

Merge tag 'trace-tools-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2024-11-22T21:24:22+00:00

Pull tracing tools updates from Steven Rostedt:

 - Add ':' to getopt option 'trace-buffer-size' in timerlat_hist for
   consistency

 - Remove unused sched_getattr define

 - Rename sched_setattr() helper to syscall_sched_setattr() to avoid
   conflicts

 - Update counters to long from int to avoid overflow

 - Add libcpupower dependency detection

 - Add --deepest-idle-state to timerlat to limit deep idle sleeps

 - Other minor clean ups and documentation changes

* tag 'trace-tools-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  verification/dot2: Improve dot parser robustness
  tools/rtla: Improve exception handling in timerlat_load.py
  tools/rtla: Enhance argument parsing in timerlat_load.py
  tools/rtla: Improve code readability in timerlat_load.py
  rtla/timerlat: Do not set params->user_workload with -U
  rtla: Documentation: Mention --deepest-idle-state
  rtla/timerlat: Add --deepest-idle-state for hist
  rtla/timerlat: Add --deepest-idle-state for top
  rtla/utils: Add idle state disabling via libcpupower
  rtla: Add optional dependency on libcpupower
  tools/build: Add libcpupower dependency detection
  rtla/timerlat: Make timerlat_hist_cpu->*_count unsigned long long
  rtla/timerlat: Make timerlat_top_cpu->*_count unsigned long long
  tools/rtla: fix collision with glibc sched_attr/sched_set_attr
  tools/rtla: drop __NR_sched_getattr
  rtla: Fix consistency in getopt_long for timerlat_hist
  rv: Fix a typo
  tools/rv: Correct the grammatical errors in the comments
  tools/rv: Correct the grammatical errors in the comments
  rtla: use the definition for stdout fd when calling isatty()

rtla/timerlat: Do not set params->user_workload with -U

2024-11-19T13:56:59+00:00

Since commit fb9e90a67ee9 ("rtla/timerlat: Make user-space threads
the default"), rtla-timerlat has been defaulting to
params->user_workload if neither that or params->kernel_workload is set.
This has unintentionally made -U, which sets only params->user_hist/top
but not params->user_workload, to behave like -u unless -k is set,
preventing the user from running a custom workload.

Example:
$ rtla timerlat hist -U -c 0 &
[1] 7413
$ python sample/timerlat_load.py 0
Error opening timerlat fd, did you run timerlat -U?
$ ps | grep timerlatu
7415 pts/4    00:00:00 timerlatu/0

Fix the issue by checking for params->user_top/hist instead of
params->user_workload when setting default thread mode.

Link: https://lore.kernel.org/20241021123140.14652-1-tglozar@redhat.com
Fixes: fb9e90a67ee9 ("rtla/timerlat: Make user-space threads the default")
Signed-off-by: Tomas Glozar 
Signed-off-by: Steven Rostedt (Google)

rtla/timerlat: Add --deepest-idle-state for hist

2024-10-17T21:13:15+00:00

Support limiting deepest idle state also for timerlat-hist.

Link: https://lore.kernel.org/20241017140914.3200454-6-tglozar@redhat.com
Signed-off-by: Tomas Glozar 
Signed-off-by: Steven Rostedt (Google)

rtla/timerlat: Add --deepest-idle-state for top

2024-10-17T21:13:15+00:00

Add option to limit deepest idle state on CPUs where timerlat is running
for the duration of the workload.

Link: https://lore.kernel.org/20241017140914.3200454-5-tglozar@redhat.com
Signed-off-by: Tomas Glozar 
Signed-off-by: Steven Rostedt (Google)

rtla/utils: Add idle state disabling via libcpupower

2024-10-17T21:13:15+00:00

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 
Signed-off-by: Steven Rostedt (Google)

rtla/timerlat: Make timerlat_hist_cpu->*_count unsigned long long

2024-10-11T17:09:57+00:00

Do the same fix as in previous commit also for timerlat-hist.

Link: https://lore.kernel.org/20241011121015.2868751-2-tglozar@redhat.com
Reported-by: Attila Fazekas 
Signed-off-by: Tomas Glozar 
Signed-off-by: Steven Rostedt (Google)

rtla/timerlat: Make timerlat_top_cpu->*_count unsigned long long

2024-10-11T17:09:57+00:00

Most fields of struct timerlat_top_cpu are unsigned long long, but the
fields {irq,thread,user}_count are int (32-bit signed).

This leads to overflow when tracing on a large number of CPUs for a long
enough time:
$ rtla timerlat top -a20 -c 1-127 -d 12h
...
  0 12:00:00   |          IRQ Timer Latency (us)        |         Thread Timer Latency (us)
CPU COUNT      |      cur       min       avg       max |      cur       min       avg       max
 1 #43200096  |        0         0         1         2 |        3         2         6        12
...
127 #43200096  |        0         0         1         2 |        3         2         5        11
ALL #119144 e4 |                  0         5         4 |                  2        28        16

The average latency should be 0-1 for IRQ and 5-6 for thread, but is
reported as 5 and 28, about 4 to 5 times more, due to the count
overflowing when summed over all CPUs: 43200096 * 127 = 5486412192,
however, 1191444898 (= 5486412192 mod MAX_INT) is reported instead, as
seen on the last line of the output, and the averages are thus ~4.6
times higher than they should be (5486412192 / 1191444898 = ~4.6).

Fix the issue by changing {irq,thread,user}_count fields to unsigned
long long, similarly to other fields in struct timerlat_top_cpu and to
the count variable in timerlat_top_print_sum.

Link: https://lore.kernel.org/20241011121015.2868751-1-tglozar@redhat.com
Reported-by: Attila Fazekas 
Signed-off-by: Tomas Glozar 
Signed-off-by: Steven Rostedt (Google)

tools/rtla: fix collision with glibc sched_attr/sched_set_attr

2024-10-11T00:31:48+00:00

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 
Signed-off-by: Steven Rostedt (Google)

tools/rtla: drop __NR_sched_getattr

2024-10-11T00:30:58+00:00

It's not used since commit 084ce16df0f0 ("tools/rtla:
Remove unused sched_getattr() function").

Link: https://lore.kernel.org/c355dc9ad23470098d6a8d0f31fbd702551c9ea8.1728552769.git.jstancek@redhat.com
Signed-off-by: Jan Stancek 
Reviewed-by: Tomas Glozar 
Signed-off-by: Steven Rostedt (Google)

rtla: Fix consistency in getopt_long for timerlat_hist

2024-10-04T23:33:38+00:00

Commit e9a4062e1527 ("rtla: Add --trace-buffer-size option") adds a new
long option to rtla utilities, but among all affected files,
timerlat_hist misses a trailing `:` in the corresponding short option
inside the getopt string (e.g. `\3:`). This patch propagates the `:`.

Although this change is not functionally required, it improves
consistency and slightly reduces the likelihood a future change would
introduce a problem.

Cc: John Kacur 
Cc: Luis Goncalves 
Cc: Tomas Glozar 
Link: https://lore.kernel.org/20240926143417.54039-1-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco 
Signed-off-by: Steven Rostedt (Google)