Currently we have in something like the sched_switch event:
field:char prev_comm[TASK_COMM_LEN]; offset:12; size:16; signed:1;
When a userspace tool such as perf tries to parse this, the
TASK_COMM_LEN is meaningless. This is done because the TRACE_EVENT() macro
simply uses a #len to show the string of the length. When the length is
an enum, we get a string that means nothing for tools.
By adding a static buffer and a mutex to protect it, we can store the
string into that buffer with snprintf and show the actual number.
Now we get:
field:char prev_comm[16]; offset:12; size:16; signed:1;
Something much more useful.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
0429578016