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author | Steven Rostedt <srostedt@redhat.com> | 2010-09-01 12:23:12 -0400 |
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committer | Steven Rostedt <rostedt@goodmis.org> | 2010-09-01 12:23:12 -0400 |
commit | f6195aa09e618d712f52bf4fa33b5293820eb93d (patch) | |
tree | a41ef0dce7ebb3e670b6e1a7214a4f558110178e | |
parent | c9cf4a019cff198ee5638323e3b0ee18886467e8 (diff) | |
download | kernel_goldelico_gta04-f6195aa09e618d712f52bf4fa33b5293820eb93d.zip kernel_goldelico_gta04-f6195aa09e618d712f52bf4fa33b5293820eb93d.tar.gz kernel_goldelico_gta04-f6195aa09e618d712f52bf4fa33b5293820eb93d.tar.bz2 |
ring-buffer: Place duplicate expression into a single function
While discussing the strictness of the 80 character limit on the
Kernel Summit Discussion mailing list, I showed examples that I
broke that limit slightly with some algorithms. In discussing with
John Linville, what looked better, I realized that two of the
80 char breaking culprits were an identical expression.
As a clean up, this patch moves the identical expression into its
own helper function and that is used instead. As a side effect,
the offending code is now under the 80 character limit. :-)
This clean up code also changes the expression from
(A - B) - C to A - (B + C)
This makes the code look a little nicer too.
Cc: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r-- | kernel/trace/ring_buffer.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 19cccc3..ef27017 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2606,6 +2606,19 @@ void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu) } EXPORT_SYMBOL_GPL(ring_buffer_record_enable_cpu); +/* + * The total entries in the ring buffer is the running counter + * of entries entered into the ring buffer, minus the sum of + * the entries read from the ring buffer and the number of + * entries that were overwritten. + */ +static inline unsigned long +rb_num_of_entries(struct ring_buffer_per_cpu *cpu_buffer) +{ + return local_read(&cpu_buffer->entries) - + (local_read(&cpu_buffer->overrun) + cpu_buffer->read); +} + /** * ring_buffer_entries_cpu - get the number of entries in a cpu buffer * @buffer: The ring buffer @@ -2614,16 +2627,13 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_enable_cpu); unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu) { struct ring_buffer_per_cpu *cpu_buffer; - unsigned long ret; if (!cpumask_test_cpu(cpu, buffer->cpumask)) return 0; cpu_buffer = buffer->buffers[cpu]; - ret = (local_read(&cpu_buffer->entries) - local_read(&cpu_buffer->overrun)) - - cpu_buffer->read; - return ret; + return rb_num_of_entries(cpu_buffer); } EXPORT_SYMBOL_GPL(ring_buffer_entries_cpu); @@ -2684,8 +2694,7 @@ unsigned long ring_buffer_entries(struct ring_buffer *buffer) /* if you care about this being correct, lock the buffer */ for_each_buffer_cpu(buffer, cpu) { cpu_buffer = buffer->buffers[cpu]; - entries += (local_read(&cpu_buffer->entries) - - local_read(&cpu_buffer->overrun)) - cpu_buffer->read; + entries += rb_num_of_entries(cpu_buffer); } return entries; |