[PATCH v2 7/7] blktrace: support filtering of BLK_TN_MESSAGE

From: Li Zefan
Date: Fri Mar 27 2009 - 01:42:21 EST


I found large bunk of the output of blktrace are BLK_TN_MESSAGE events:

% blktrace -d /dev/sda -o - | blkparse -i - -o ~/blk.log
(after some seconds)
% cat ~/blk.log | wc -l
69041
% cat ~/blk.log | grep "m N" | wc -l
38232

It will be useful to be able to filter those events.

Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
---
kernel/trace/blktrace.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 947c5b3..dcabe59 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -131,6 +131,9 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
!blk_tracer_enabled))
return;

+ if (!(bt->act_mask & BLK_TC_NOTIFY))
+ return;
+
local_irq_save(flags);
buf = per_cpu_ptr(bt->msg_data, smp_processor_id());
va_start(args, fmt);
@@ -1366,6 +1369,7 @@ static const struct {
{ BLK_TC_COMPLETE, "complete" },
{ BLK_TC_FS, "fs" },
{ BLK_TC_PC, "pc" },
+ { BLK_TC_NOTIFY, "notify" },
{ BLK_TC_AHEAD, "ahead" },
{ BLK_TC_META, "meta" },
{ BLK_TC_DISCARD, "discard" },
--
1.5.4.rc3

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