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| author | Steven Rostedt (Red Hat) <[email protected]> | 2015-09-22 21:13:19 +0000 |
|---|---|---|
| committer | Steven Rostedt <[email protected]> | 2015-10-26 01:33:54 +0000 |
| commit | 7904b5c4988e18b50056b5e71a3ffca752a8a451 (patch) | |
| tree | 4319a3e6fe143e6404420f885275cb1f7c87a1a4 /lib/mpi/mpi-cmp.c | |
| parent | ftrace: Calculate the correct dyn_ftrace number to report to the userspace (diff) | |
| download | kernel-7904b5c4988e18b50056b5e71a3ffca752a8a451.tar.gz kernel-7904b5c4988e18b50056b5e71a3ffca752a8a451.zip | |
tracepoint: Give priority to probes of tracepoints
In order to guarantee that a probe will be called before other probes that
are attached to a tracepoint, there needs to be a mechanism to provide
priority of one probe over the others.
Adding a prio field to the struct tracepoint_func, which lets the probes be
sorted by the priority set in the structure. If no priority is specified,
then a priority of 10 is given (this is a macro, and perhaps may be changed
in the future).
Now probes may be added to affect other probes that are attached to a
tracepoint with a guaranteed order.
One use case would be to allow tracing of tracepoints be able to filter by
pid. A special (higher priority probe) may be added to the sched_switch
tracepoint and set the necessary flags of the other tracepoints to notify
them if they should be traced or not. In case a tracepoint is enabled at the
sched_switch tracepoint too, the order of the two are not random.
Cc: Mathieu Desnoyers <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
Diffstat (limited to 'lib/mpi/mpi-cmp.c')
0 files changed, 0 insertions, 0 deletions