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: sta...@vger.kernel.org
Fixes: ed774f7481fa ("rtla/timerlat_hist: Add timerlat user-space support")
Signed-off-by: Tomas Glozar <tglo...@redhat.com>
---
tools/tracing/rtla/src/timerlat_hist.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/tools/tracing/rtla/src/timerlat_hist.c
b/tools/tracing/rtla/src/timerlat_hist.c
index 4403cc4eba30..66dbc034bdc7 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -1100,12 +1100,15 @@ timerlat_hist_apply_config(struct osnoise_tool *tool,
struct timerlat_hist_param
}
}
- if (params->user_hist) {
- retval = osnoise_set_workload(tool->context, 0);
- if (retval) {
- err_msg("Failed to set OSNOISE_WORKLOAD option\n");
- goto out_err;
- }
+ /*
+ * Set workload according to type of thread if the kernel supports it.
+ * On kernels without support, user threads will have already failed
+ * on missing timerlat_fd, and kernel threads do not need it.
+ */
+ retval = osnoise_set_workload(tool->context, params->kernel_workload);
+ if (retval < -1) {
+ err_msg("Failed to set OSNOISE_WORKLOAD option\n");
+ goto out_err;
}
return 0;
--
2.47.1
