On 2016/4/1 2:08, Arnaldo Carvalho de Melo wrote:
Hi Wang,
Trying to get back at working with 'perf trace' + BPF and I'm
noticing that the perf_event_attr->sample_type for the BPF events are
different than the ones for the raw_syscalls:sys_{enter,exit} or to
other tracepoint events we may ask 'perf trace' to set up, for instance,
for:
perf trace -vv -T --ev sched:sched_switch --ev bpf-output/no-inherit,name=evt/
--ev /home/acme/bpf/test_bpf_trace.c/map:channel.event=evt/ usleep 10
We get these sample types (full perf_event_attr dump at the end of this
message):
sched:sched_switch:
sample_type IP|TID|TIME|CPU|PERIOD|RAW|IDENTIFIER
[root@jouet ~]# perf probe -l
perf_bpf_probe:func_begin (on SyS_nanosleep@linux/kernel/time/hrtimer.c)
perf_bpf_probe:func_end (on SyS_nanosleep%return@linux/kernel/time/hrtimer.c)
sample_type IP|TID|RAW|IDENTIFIER
raw_syscalls:sys_{enter,exit}:
sample_type IP|TID|TIME|CPU|PERIOD|RAW|IDENTIFIER
I guess this is an interaction with that "no-inherit" part, probably we need to
set PERF_SAMPLE_TIME by some other means...
Please see [1]. Not related to no-inherit, just because the bpf-output event
is not a tracepoint.
And glad to see you restart working on my patches again!
Thank you.
[1]
http://lkml.kernel.org/g/1459517202-42320-1-git-send-email-wangn...@huawei.com
- Arnaldo
