diff options
| author | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2023-08-23 01:26:12 +0900 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2023-08-23 09:40:28 +0900 |
| commit | c440adfbe30257dde905adc1fce51131145f7245 (patch) | |
| tree | 7d165f8b5f7f0234ff77477653865ecf1ec09714 /kernel/trace/trace.c | |
| parent | 302db0f5b3d87e3b9de2d82bfe11c1d7db84d0c2 (diff) | |
tracing/probes: Support BTF based data structure field access
Using BTF to access the fields of a data structure. You can use this
for accessing the field with '->' or '.' operation with BTF argument.
# echo 't sched_switch next=next->pid vruntime=next->se.vruntime' \
> dynamic_events
# echo 1 > events/tracepoints/sched_switch/enable
# head -n 40 trace | tail
<idle>-0 [000] d..3. 272.565382: sched_switch: (__probestub_sched_switch+0x4/0x10) next=26 vruntime=956533179
kcompactd0-26 [000] d..3. 272.565406: sched_switch: (__probestub_sched_switch+0x4/0x10) next=0 vruntime=0
<idle>-0 [000] d..3. 273.069441: sched_switch: (__probestub_sched_switch+0x4/0x10) next=9 vruntime=956533179
kworker/0:1-9 [000] d..3. 273.069464: sched_switch: (__probestub_sched_switch+0x4/0x10) next=26 vruntime=956579181
kcompactd0-26 [000] d..3. 273.069480: sched_switch: (__probestub_sched_switch+0x4/0x10) next=0 vruntime=0
<idle>-0 [000] d..3. 273.141434: sched_switch: (__probestub_sched_switch+0x4/0x10) next=22 vruntime=956533179
kworker/u2:1-22 [000] d..3. 273.141461: sched_switch: (__probestub_sched_switch+0x4/0x10) next=0 vruntime=0
<idle>-0 [000] d..3. 273.480872: sched_switch: (__probestub_sched_switch+0x4/0x10) next=22 vruntime=956585857
kworker/u2:1-22 [000] d..3. 273.480905: sched_switch: (__probestub_sched_switch+0x4/0x10) next=70 vruntime=959533179
sh-70 [000] d..3. 273.481102: sched_switch: (__probestub_sched_switch+0x4/0x10) next=0 vruntime=0
Link: https://lore.kernel.org/all/169272157251.160970.9318175874130965571.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b8870078ef58d..58ebda1cf9005 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5717,7 +5717,8 @@ static const char readme_msg[] = "\t fetcharg: (%<register>|$<efield>), @<address>, @<symbol>[+|-<offset>],\n" #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API #ifdef CONFIG_PROBE_EVENTS_BTF_ARGS - "\t $stack<index>, $stack, $retval, $comm, $arg<N>, <argname>\n" + "\t $stack<index>, $stack, $retval, $comm, $arg<N>,\n" + "\t <argname>[->field[->field|.field...]],\n" #else "\t $stack<index>, $stack, $retval, $comm, $arg<N>,\n" #endif |