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author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2015-09-22 17:13:19 -0400 |
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committer | Steven Rostedt <rostedt@goodmis.org> | 2015-10-25 21:33:54 -0400 |
commit | 7904b5c4988e18b50056b5e71a3ffca752a8a451 (patch) | |
tree | 4319a3e6fe143e6404420f885275cb1f7c87a1a4 /kernel/trace | |
parent | 883a1e867e0fe7c2dc2e5844ef692f80177631d5 (diff) | |
download | linux-stable-7904b5c4988e18b50056b5e71a3ffca752a8a451.tar.gz linux-stable-7904b5c4988e18b50056b5e71a3ffca752a8a451.tar.bz2 linux-stable-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 <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
0 files changed, 0 insertions, 0 deletions