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

rtla: Fix uninitialized variable found

2023-10-30T18:00:12+00:00

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_top: Add timerlat user-space support

2023-06-13T20:38:51+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 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: 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: Define syscall numbers for riscv

2022-07-31T21:04:05+00:00

RISC-V uses the same (generic) syscall numbers as ARM64. Link: https://lkml.kernel.org/r/mvma68wl2ul.fsf@suse.de Signed-off-by: Andreas Schwab Acked-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla/utils: Use calloc and check the potential memory allocation failure

2022-07-12T01:14:29+00:00

Replace malloc with calloc and add memory allocating check of mon_cpus before used. Link: https://lkml.kernel.org/r/20220615073348.6891-1-jianchunfu@cmss.chinamobile.com Fixes: 7d0dc9576dc3 ("rtla/timerlat: Add --dma-latency option") Signed-off-by: jianchunfu Acked-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Remove procps-ng dependency

2022-05-26T19:20:46+00:00

Daniel Wagner reported to me that readproc.h got deprecated. Also, while the procps-ng library was available on Fedora, it was not available on RHEL, which is a piece of evidence that it was not that used. rtla uses procps-ng only to find the PID of the tracers' workload. I used the procps-ng library to avoid reinventing the wheel. But in this case, reinventing the wheel took me less time than the time we already took trying to work around problems. Implement a function that reads /proc/ entries, checking if: - the entry is a directory - the directory name is composed only of digits (PID) - the directory contains the comm file - the comm file contains a comm that matches the tracers' workload prefix. - then return true; otherwise, return false. And use it instead of procps-ng. Link: https://lkml.kernel.org/r/e8276e122ee9eb2c5a0ba8e673fb6488b924b825.1652423574.git.bristot@kernel.org Cc: John Kacur Cc: Steven Rostedt Cc: Tao Zhou Fixes: b1696371d865 ("rtla: Helper functions for rtla") Reported-by: Daniel Wagner Reviewed-by: Daniel Wagner Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Fix __set_sched_attr error message

2022-05-26T19:18:29+00:00

rtla's function __set_sched_attr() was borrowed from stalld, but I forgot to update the error message to something meaningful for rtla. Update the error message from: boost_with_deadline failed to boost pid PID: STRERROR to a proper one: Failed to set sched attributes to the pid PID: STRERROR Link: https://lkml.kernel.org/r/a2d19b2c53f6512aefd1ee7f8c1bd19d4fc8b99d.1651247710.git.bristot@kernel.org Link: https://lore.kernel.org/r/eeded730413e7feaa13f946924bcf2cbf7dd9561.1650617571.git.bristot@kernel.org/ Fixes: b1696371d865 ("rtla: Helper functions for rtla") Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)