• Steven Rostedt's avatar
    tracing/events: Show real number in array fields · 04295780
    Steven Rostedt authored
    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: default avatarSteven Rostedt <rostedt@goodmis.org>
    04295780
ftrace.h 21.1 KB