út 21. 10. 2025 v 19:32 odesílatel Crystal Wood <[email protected]> napsal:
>
> On Tue, 2025-10-21 at 13:02 -0400, Steven Rostedt wrote:
> >
> > Note, trace_array_printk() (which trace_array_init_printk()) only works for
> > instances and does not print into the top level trace buffer.
>
> Yes, it's for instances, such as the ones rtla creates.
>
> -Crystal
>
Right, it actually works with the trace instance, when set up properly:
[root@cs9 rtla]# ./rtla timerlat hist -T 1 -c 0 -e
bpf_trace:bpf_trace_printk --on-end trace --on-end shell,command='grep
bpf_trace_printk timerlat_trace.txt' --bpf-action
example/timerlat_bpf_action.o
# RTLA timerlat histogram
# Time unit is microseconds (us)
# Duration: 0 00:00:01
Index IRQ-000 Thr-000 Usr-000
6 1 0 0
21 0 1 0
over: 0 0 0
count: 1 1 0
min: 6 21 -
avg: 6 21 -
max: 6 21 -
ALL: IRQ Thr Usr
count: 1 1 0
min: 6 21 -
avg: 6 21 -
max: 6 21 -
Saving trace to timerlat_trace.txt
timerlatu/0-47791 [000] ...22 863353.286497: bpf_trace_printk:
Latency: 21282
Tomas
