kernel/linux.git/tools/tracing/rtla/src/timerlat_hist.c, branch v6.12.80

rtla/timerlat_hist: Abort event processing on second signal

2025-02-21T13:01:25+00:00

[ Upstream commit d6899e560366e10141189697502bc5521940c588 ] If either SIGINT is received twice, or after a SIGALRM (that is, after timerlat was supposed to stop), abort processing events currently left in the tracefs buffer and exit immediately. This allows the user to exit rtla without waiting for processing all events, should that take longer than wanted, at the cost of not processing all samples. Cc: John Kacur Cc: Luis Goncalves Cc: Gabriele Monaco Link: https://lore.kernel.org/20250116144931.649593-5-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin

rtla/timerlat_hist: Stop timerlat tracer on signal

2025-02-17T09:05:43+00:00

commit c73cab9dbed04d8f65ca69177b4b21ed3e09dfa7 upstream. Currently, when either SIGINT from the user or SIGALRM from the duration timer is caught by rtla-timerlat, stop_tracing is set to break out of the main loop. This is not sufficient for cases where the timerlat tracer is producing more data than rtla can consume, since in that case, rtla is looping indefinitely inside tracefs_iterate_raw_events, never reaches the check of stop_tracing and hangs. In addition to setting stop_tracing, also stop the timerlat tracer on received signal (SIGINT or SIGALRM). This will stop new samples so that the existing samples may be processed and tracefs_iterate_raw_events eventually exits. Cc: stable@vger.kernel.org Cc: John Kacur Cc: Luis Goncalves Cc: Gabriele Monaco Link: https://lore.kernel.org/20250116144931.649593-3-tglozar@redhat.com Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode") Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads

2025-02-17T09:05:42+00:00

commit d8d866171a414ed88bd0d720864095fd75461134 upstream. When using rtla timerlat with userspace threads (-u or -U), rtla disables the OSNOISE_WORKLOAD option in /sys/kernel/tracing/osnoise/options. This option is not re-enabled in a subsequent run with kernel-space threads, leading to rtla collecting no results if the previous run exited abnormally: $ rtla timerlat hist -u ^\Quit (core dumped) $ rtla timerlat hist -k -d 1s Index over: count: min: avg: max: ALL: IRQ Thr Usr count: 0 0 0 min: - - - avg: - - - max: - - - The issue persists until OSNOISE_WORKLOAD is set manually by running: $ echo OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options Set OSNOISE_WORKLOAD when running rtla with kernel-space threads if available to fix the issue. Cc: stable@vger.kernel.org Cc: John Kacur Cc: Luis Goncalves Link: https://lore.kernel.org/20250107144823.239782-3-tglozar@redhat.com Fixes: ed774f7481fa ("rtla/timerlat_hist: Add timerlat user-space support") Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

rtla/timerlat: Fix histogram ALL for zero samples

2025-01-02T09:34:22+00:00

commit 6cc45f8c1f898570916044f606be9890d295e129 upstream. rtla timerlat hist currently computers the minimum, maximum and average latency even in cases when there are zero samples. This leads to nonsensical values being calculated for maximum and minimum, and to divide by zero for average. A similar bug is fixed by 01b05fc0e5f3 ("rtla/timerlat: Fix histogram report when a cpu count is 0") but the bug still remains for printing the sum over all CPUs in timerlat_print_stats_all. The issue can be reproduced with this command: $ rtla timerlat hist -U -d 1s Index over: count: min: avg: max: Floating point exception (core dumped) (There are always no samples with -U unless the user workload is created.) Fix the bug by omitting max/min/avg when sample count is zero, displaying a dash instead, just like we already do for the individual CPUs. The logic is moved into a new function called format_summary_value, which is used for both the individual CPUs and for the overall summary. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/20241127134130.51171-1-tglozar@redhat.com Fixes: 1462501c7a8 ("rtla/timerlat: Add a summary for hist mode") Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

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

2024-12-14T19:03:59+00:00

[ Upstream commit 76b3102148135945b013797fac9b206273f0f777 ] 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) Signed-off-by: Sasha Levin

rtla: Fix consistency in getopt_long for timerlat_hist

2024-12-14T19:03:58+00:00

[ Upstream commit cfb1ea216c1656a4112becbc4bf757891933b902 ] 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) Signed-off-by: Sasha Levin

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

2024-12-05T13:02:17+00:00

[ Upstream commit fcbc60d7dc4b125c8de130aa1512e5d20726c06e ] 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) Signed-off-by: Sasha Levin

rtla: Fix -t\--trace[=file]

2024-05-16T14:49:10+00:00

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 Signed-off-by: John Kacur Signed-off-by: Daniel Bristot de Oliveira

rtla/timerlat: Fix histogram report when a cpu count is 0

2024-05-16T14:45:40+00:00

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 Signed-off-by: John Kacur Signed-off-by: Daniel Bristot de Oliveira

rtla: Add --trace-buffer-size option

2024-05-16T14:44:34+00:00

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 Cc: Juri Lelli Cc: John Kacur Signed-off-by: Daniel Bristot de Oliveira