pm24.git/tools/tracing, branch rust-6.8

rtla: Fix uninitialized variable found

2023-10-30T18:00:12Z

Variable found is not being initialized, in the case where the desired mount is not found the variable contains garbage. Fix this by initializing it to zero. Link: https://lore.kernel.org/all/20230727150117.627730-1-colin.i.king@gmail.com/ Fixes: a957cbc02531 ("rtla: Add -C cgroup support") Signed-off-by: Colin Ian King Signed-off-by: Daniel Bristot de Oliveira

rtla/timerlat: Do not stop user-space if a cpu is offline

2023-09-22T12:43:46Z

If no CPU list is passed, timerlat in user-space will dispatch one thread per sysconf(_SC_NPROCESSORS_CONF). However, not all CPU might be available, for instance, if HT is disabled. Currently, rtla timerlat is stopping the session if an user-space thread cannot set affinity to a CPU, or if a running user-space thread is killed. However, this is too restrictive. So, reduce the error to a debug message, and rtla timerlat run as long as there is at least one user-space thread alive. Link: https://lore.kernel.org/lkml/59cf2c882900ab7de91c6ee33b382ac7fa6b4ed0.1694781909.git.bristot@kernel.org Fixes: cdca4f4e5e8e ("rtla/timerlat_top: Add timerlat user-space support") Signed-off-by: Daniel Bristot de Oliveira

rtla/timerlat_aa: Fix previous IRQ delay for IRQs that happens after thread sample

2023-09-12T13:43:17Z

timerlat auto-analysis takes note of all IRQs, before or after the execution of the timerlat thread. Because we cannot go backward in the trace (we will fix it when moving to trace-cmd lib?), timerlat aa take note of the last IRQ execution in the waiting for the IRQ state, and then print it if it is executed after the expected timer IRQ starting time. After the thread sample, the timerlat starts recording the next IRQs as "previous" irq for the next occurrence. However, if an IRQ happens after the thread measurement but before the tracing stops, it is classified as a previous IRQ. That is not wrong, as it can be "previous" for the subsequent activation. What is wrong is considering it as a potential source for the last activation. Ignore the IRQ interference that happens after the IRQ starting time for now. A future improvement for timerlat can be either keeping a list of previous IRQ execution or using the trace-cmd library. Still, it requires further investigation - it is a new feature. Link: https://lore.kernel.org/lkml/a44a3f5c801dcc697bacf7325b65d4a5b0460537.1691162043.git.bristot@kernel.org Fixes: 27e348b221f6 ("rtla/timerlat: Add auto-analysis core") Signed-off-by: Daniel Bristot de Oliveira

rtla/timerlat_aa: Fix negative IRQ delay

2023-09-12T13:43:17Z

When estimating the IRQ timer delay, we are dealing with two different clock sources: the external clock source that timerlat uses as a reference and the clock used by the tracer. There are also two moments: the time reading the clock and the timer in which the event is placed in the buffer (the trace event timestamp). If the processor is slow or there is some hardware noise, the difference between the timestamp and the external clock, read can be longer than the IRQ handler delay, resulting in a negative time. If so, set IRQ to start delay as 0. In the end, it is less near-zero and relevant then the noise. Link: https://lore.kernel.org/lkml/a066fb667c7136d86dcddb3c7ccd72587db3e7c7.1691162043.git.bristot@kernel.org Fixes: 27e348b221f6 ("rtla/timerlat: Add auto-analysis core") Signed-off-by: Daniel Bristot de Oliveira

rtla/timerlat_aa: Zero thread sum after every sample analysis

2023-09-12T13:43:17Z

The thread thread_thread_sum accounts for thread interference during a single activation. It was not being zeroed, so it was accumulating thread interference over all activations. It was not that visible when timerlat was the highest priority. Link: https://lore.kernel.org/lkml/97bff55b0141f2d01b47d9450a5672fde147b89a.1691162043.git.bristot@kernel.org Fixes: 27e348b221f6 ("rtla/timerlat: Add auto-analysis core") Signed-off-by: Daniel Bristot de Oliveira

rtla/timerlat_hist: Add timerlat user-space support

2023-06-13T20:41:14Z

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/timerlat_top: Add timerlat user-space support

2023-06-13T20:38:51Z

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

rtla/hwnoise: Reduce runtime to 75%

2023-06-13T20:38:11Z

osnoise runs 100% of time by default. It makes sense because osnoise is preemptive. hwnoise checks preemption once a second, so it reduces system progress. Reduce runtime to 75% to avoid problems by default. I added a Fixes as it might avoid problems for first time users as it lands on distros. Link: https://lkml.kernel.org/r/af0b7113ffc00031b9af4bb40ef5889a27dadf8c.1686066600.git.bristot@kernel.org Cc: William White Cc: Jonathan Corbet Tested-by: Juri Lelli Fixes: 1f428356c38d ("rtla: Add hwnoise tool") Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Start the tracers after creating all instances

2023-06-13T20:37:05Z

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

2023-06-13T20:35:46Z

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)