• Joel Fernandes's avatar
    tracing: Add support for recording tgid of tasks · d914ba37
    Joel Fernandes authored
    Inorder to support recording of tgid, the following changes are made:
    
    * Introduce a new API (tracing_record_taskinfo) to additionally record the tgid
      along with the task's comm at the same time. This has has the benefit of not
      setting trace_cmdline_save before all the information for a task is saved.
    * Add a new API tracing_record_taskinfo_sched_switch to record task information
      for 2 tasks at a time (previous and next) and use it from sched_switch probe.
    * Preserve the old API (tracing_record_cmdline) and create it as a wrapper
      around the new one so that existing callers aren't affected.
    * Reuse the existing sched_switch and sched_wakeup probes to record tgid
      information and add a new option 'record-tgid' to enable recording of tgid
    
    When record-tgid option isn't enabled to being with, we take care to make sure
    that there's isn't memory or runtime overhead.
    
    Link: http://lkml.kernel.org/r/20170627020155.5139-1-joelaf@google.com
    
    Cc: kernel-team@android.com
    Cc: Ingo Molnar <mingo@redhat.com>
    Tested-by: default avatarMichael Sartain <mikesart@gmail.com>
    Signed-off-by: default avatarJoel Fernandes <joelaf@google.com>
    Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
    d914ba37
trace_sched_switch.c 3 KB