tree b0997862babd5e474c500b1b4c522f3a03842106
parent 45677454dd6d128608117abe7dcd2bdfdd7cdf72
author Steven Rostedt <srostedt@redhat.com> 1289619131 -0500
committer Steven Rostedt <rostedt@goodmis.org> 1290179927 -0500

tracing/events: Show real number in array fields

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>