kernel/linux.git/tools/tracing/rtla/src/timerlat_hist.c, branch v6.7.3

rtla/timerlat_hist: Add timerlat user-space support

2023-06-13T20:41:14+00:00

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 hist -u -c 1-3 -d 600 # RTLA timerlat histogram # Time unit is microseconds (us) # Duration: 0 00:10:01 Index IRQ-001 Thr-001 Usr-001 IRQ-002 Thr-002 Usr-002 IRQ-003 Thr-003 Usr-003 0 477555 0 0 425287 0 0 474357 0 0 1 122385 7998 0 174616 1921 0 125412 3138 0 2 47 587376 492150 89 594717 447830 147 593463 454872 3 11 2549 101930 7 2682 145580 64 2530 138680 4 3 1954 2833 1 463 4917 11 548 4656 5 0 60 1037 0 138 1117 6 179 1130 6 0 26 1837 0 38 277 1 76 339 7 0 15 143 0 28 147 2 37 156 8 0 10 23 0 11 75 0 12 80 9 0 7 17 0 0 26 0 11 42 10 0 2 11 0 0 18 0 2 20 11 0 0 7 0 1 8 0 2 12 12 0 0 6 0 1 4 0 2 8 13 0 1 3 0 0 0 0 0 1 14 0 1 0 0 0 1 0 0 2 15 0 1 0 0 0 0 0 0 2 16 0 1 2 0 0 0 0 0 0 17 0 0 1 0 0 0 0 0 0 19 0 0 1 0 0 0 0 0 0 over: 0 0 0 0 0 0 0 0 0 count: 600001 600001 600001 600000 600000 600000 600000 600000 600000 min: 0 1 2 0 1 2 0 1 2 avg: 0 1 2 0 2 2 0 2 2 max: 4 16 19 4 12 14 7 12 15 The tuning setup like -p or -C work for the user-space threads as well. Link: https://lkml.kernel.org/r/b6a042d55003c4a67ff7dce28d96044b7044f00d.1686066600.git.bristot@kernel.org Cc: William White Cc: Jonathan Corbet Tested-by: Juri Lelli Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Start the tracers after creating all instances

2023-06-13T20:37:05+00:00

Group all start tracing after finishing creating all instances. The tracing instance starts first for the case of hitting a stop tracing while enabling other instances. The trace instance is the one with most valuable information. Link: https://lkml.kernel.org/r/67da7a703a56f75d7cd46568525145a65501a7e8.1686066600.git.bristot@kernel.org Cc: William White Cc: Jonathan Corbet Tested-by: Juri Lelli Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla/timerlat_hist: Add auto-analysis support

2023-06-13T20:35:46+00:00

Add auto-analysis to timerlat hist, including the --no-aa option to reduce overhead and --dump-task. --aa-only was not added as it is already on timerlat top. Link: https://lkml.kernel.org/r/c2693f47ee83e659a7723fed8035f5d2534f528e.1686066600.git.bristot@kernel.org Cc: William White Cc: Jonathan Corbet Tested-by: Juri Lelli Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Automatically move rtla to a house-keeping cpu

2023-06-13T20:30:13+00:00

When the user sets -c try to move rtla out of the , even without an -H option. This is useful to avoid having rtla interfering with the workload. This works by removing 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 Cc: Jonathan Corbet Tested-by: Juri Lelli Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Change monitored_cpus from char * to cpu_set_t

2023-06-13T20:28:56+00:00

Use a cpumask instead of a char *, reducing memory footprint and code. No functional change, and in preparation for auto house-keeping. Link: https://lkml.kernel.org/r/54c46293261d13cb1042d0314486539eeb45fe5d.1686066600.git.bristot@kernel.org Cc: William White Cc: Jonathan Corbet Tested-by: Juri Lelli Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Add --house-keeping option

2023-06-13T20:26:03+00:00

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

rtla: Add -C cgroup support

2023-06-13T20:25:13+00:00

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

rtla: Fix tracer name

2022-08-10T15:43:59+00:00

The correct tracer name is timerlat and not timelat. Link: https://lore.kernel.org/linux-trace-devel/20220808180343.22262-1-alexandre.vicenzi@suse.com Signed-off-by: Alexandre Vicenzi Signed-off-by: Steven Rostedt (Google)

rtla: Avoid record NULL pointer dereference

2022-05-26T19:18:28+00:00

Fix the following null/deref_null.cocci errors: ./tools/tracing/rtla/src/osnoise_hist.c:870:31-36: ERROR: record is NULL but dereferenced. ./tools/tracing/rtla/src/osnoise_top.c:650:31-36: ERROR: record is NULL but dereferenced. ./tools/tracing/rtla/src/timerlat_hist.c:905:31-36: ERROR: record is NULL but dereferenced. ./tools/tracing/rtla/src/timerlat_top.c:700:31-36: ERROR: record is NULL but dereferenced. "record" is NULL before calling osnoise_init_trace_tool. Add a tag "out_free" to avoid dereferring a NULL pointer. Link: https://lkml.kernel.org/r/ae0e4500d383db0884eb2820286afe34ca303778.1651247710.git.bristot@kernel.org Link: https://lore.kernel.org/r/20220408151406.34823-1-wanjiabing@vivo.com/ Cc: kael_w@yeah.net Cc: Daniel Bristot de Oliveira Fixes: 51d64c3a1819 ("rtla: Add -e/--event support") Acked-by: Daniel Bristot de Oliveira Signed-off-by: Wan Jiabing Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Tools main loop cleanup

2022-03-15T18:36:50+00:00

I probably started using "do {} while();", but changed all but osnoise_top to "while(){};" leaving the ; behind. Cleanup the main loop code, making all tools use "while() {}" Changcheng Deng reported this problem, as reported by coccicheck: Fix the following coccicheck review: ./tools/tracing/rtla/src/timerlat_hist.c: 800: 2-3: Unneeded semicolon ./tools/tracing/rtla/src/osnoise_hist.c: 776: 2-3: Unneeded semicolon ./tools/tracing/rtla/src/timerlat_top.c: 596: 2-3: Unneeded semicolon Link: https://lkml.kernel.org/r/3c1642110aa87c396f5da4a037dabc72dbb9c601.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira Cc: Clark Williams Cc: Juri Lelli Cc: Jonathan Corbet Reported-by: Changcheng Deng Reported-by: Zeal Robot Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)