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| author | Jerry Snitselaar <jsnitsel@redhat.com> | 2015-04-30 08:10:24 -0700 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2015-05-12 15:56:57 -0400 |
| commit | 7e255d346c12888f7cce4b89a03a5fe5e9196ab1 (patch) | |
| tree | b87449fa2978ae7d1975b566e1936784a57cd36b /kernel/trace | |
| parent | 755a27e7e4c817dd51ade41668b380f26026899c (diff) | |
| download | linux-7e255d346c12888f7cce4b89a03a5fe5e9196ab1.tar.bz2 | |
tracing: Export tracing clock functions
Critical tracepoint hooks should never call anything that takes a lock,
so they are unable to call getrawmonotonic() or ktime_get().
Export the rest of the tracing clock functions so can be used in
tracepoint hooks.
Background: We have a customer that adds their own module and registers
a tracepoint hook to sched_wakeup. They were using ktime_get() for a
time source, but it grabs a seq lock and caused a deadlock to occur.
Link: http://lkml.kernel.org/r/1430406624-22609-1-git-send-email-jsnitsel@redhat.com
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/trace_clock.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c index 57b67b1f24d1..0f06532a755b 100644 --- a/kernel/trace/trace_clock.c +++ b/kernel/trace/trace_clock.c @@ -56,6 +56,7 @@ u64 notrace trace_clock(void) { return local_clock(); } +EXPORT_SYMBOL_GPL(trace_clock); /* * trace_jiffy_clock(): Simply use jiffies as a clock counter. @@ -68,6 +69,7 @@ u64 notrace trace_clock_jiffies(void) { return jiffies_64_to_clock_t(jiffies_64 - INITIAL_JIFFIES); } +EXPORT_SYMBOL_GPL(trace_clock_jiffies); /* * trace_clock_global(): special globally coherent trace clock @@ -123,6 +125,7 @@ u64 notrace trace_clock_global(void) return now; } +EXPORT_SYMBOL_GPL(trace_clock_global); static atomic64_t trace_counter; |