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| author | Steven Rostedt | 2012-11-02 23:33:05 +0100 |
|---|---|---|
| committer | Steven Rostedt | 2013-01-23 05:38:03 +0100 |
| commit | 567cd4da54ff45513d2ca1f0e3cb9ba45b66d6cf (patch) | |
| tree | 1a9e719a31643138fa76ecf556401fee1f536813 /kernel/trace/trace.h | |
| parent | ftrace: Use only the preempt version of function tracing (diff) | |
| download | kernel-qcow2-linux-567cd4da54ff45513d2ca1f0e3cb9ba45b66d6cf.tar.gz kernel-qcow2-linux-567cd4da54ff45513d2ca1f0e3cb9ba45b66d6cf.tar.xz kernel-qcow2-linux-567cd4da54ff45513d2ca1f0e3cb9ba45b66d6cf.zip | |
ring-buffer: User context bit recursion checking
Using context bit recursion checking, we can help increase the
performance of the ring buffer.
Before this patch:
# echo function > /debug/tracing/current_tracer
# for i in `seq 10`; do ./hackbench 50; done
Time: 10.285
Time: 10.407
Time: 10.243
Time: 10.372
Time: 10.380
Time: 10.198
Time: 10.272
Time: 10.354
Time: 10.248
Time: 10.253
(average: 10.3012)
Now we have:
# echo function > /debug/tracing/current_tracer
# for i in `seq 10`; do ./hackbench 50; done
Time: 9.712
Time: 9.824
Time: 9.861
Time: 9.827
Time: 9.962
Time: 9.905
Time: 9.886
Time: 10.088
Time: 9.861
Time: 9.834
(average: 9.876)
a 4% savings!
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.h')
| -rw-r--r-- | kernel/trace/trace.h | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index c203a51dd412..04a2c7ab1735 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -291,11 +291,6 @@ struct tracer { /* Only current can touch trace_recursion */ -#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0) -#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0) - -/* Ring buffer has the 10 LSB bits to count */ -#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff) /* * For function tracing recursion: @@ -323,7 +318,13 @@ struct tracer { * caller, and we can skip the current check. */ enum { - TRACE_FTRACE_BIT = 11, + TRACE_BUFFER_BIT, + TRACE_BUFFER_NMI_BIT, + TRACE_BUFFER_IRQ_BIT, + TRACE_BUFFER_SIRQ_BIT, + + /* Start of function recursion bits */ + TRACE_FTRACE_BIT, TRACE_FTRACE_NMI_BIT, TRACE_FTRACE_IRQ_BIT, TRACE_FTRACE_SIRQ_BIT, |