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authorLi Zefan <lizf@cn.fujitsu.com>2009-04-15 11:02:56 +0800
committerIngo Molnar <mingo@elte.hu>2009-04-16 10:11:01 +0200
commitf3948f8857ef5de239f28a61dddb1554a0ae4c2c (patch)
tree62e5568c18b944d086366510fb0ff8ed71682897 /kernel/trace/blktrace.c
parent1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82 (diff)
blktrace: fix context-info when mixed-using blk tracer and trace events
When current tracer is set to blk tracer, TRACE_ITER_CONTEXT_INFO is unset, but actually context-info is printed: pdflush-431 [000] 821.181576: 8,0 P N [pdflush] And then if we enable TRACE_ITER_CONTEXT_INFO: # echo context-info > trace_options We'll see context-info printed twice. What's worse, when we use blk tracer and trace events at the same time, we'll see no context-info for trace events at all: jbd2_commit_logging: dev dm-0:8 transaction 333227 jbd2_end_commit: dev dm-0:8 transaction 333227 head 332814 rm-25433 [001] 9578.307485: 8,18 m N cfq25433 slice expired t=0 rm-25433 [001] 9578.307486: 8,18 m N cfq25433 put_queue This patch adds blk_tracer->set_flags(), and context-info flag is unset only when we set the output to classic mode. Note after this patch, one should unset context-info explicitly if he wants to get binary output that can be parsed by blkparse: # echo nocontext-info > trace_options # echo bin > trace_options # echo blk > current_tracer # cat trace_pipe | blkparse -i - Reported-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <49E54E60.50408@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/blktrace.c')
-rw-r--r--kernel/trace/blktrace.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 8e7c5da3a3e..c32062bd10b 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1211,7 +1211,6 @@ static void blk_tracer_print_header(struct seq_file *m)
static void blk_tracer_start(struct trace_array *tr)
{
blk_tracer_enabled = true;
- trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
}
static int blk_tracer_init(struct trace_array *tr)
@@ -1224,7 +1223,6 @@ static int blk_tracer_init(struct trace_array *tr)
static void blk_tracer_stop(struct trace_array *tr)
{
blk_tracer_enabled = false;
- trace_flags |= TRACE_ITER_CONTEXT_INFO;
}
static void blk_tracer_reset(struct trace_array *tr)
@@ -1289,9 +1287,6 @@ out:
static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
int flags)
{
- if (!trace_print_context(iter))
- return TRACE_TYPE_PARTIAL_LINE;
-
return print_one_line(iter, false);
}
@@ -1326,6 +1321,18 @@ static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
return print_one_line(iter, true);
}
+static int blk_tracer_set_flag(u32 old_flags, u32 bit, int set)
+{
+ /* don't output context-info for blk_classic output */
+ if (bit == TRACE_BLK_OPT_CLASSIC) {
+ if (set)
+ trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
+ else
+ trace_flags |= TRACE_ITER_CONTEXT_INFO;
+ }
+ return 0;
+}
+
static struct tracer blk_tracer __read_mostly = {
.name = "blk",
.init = blk_tracer_init,
@@ -1335,6 +1342,7 @@ static struct tracer blk_tracer __read_mostly = {
.print_header = blk_tracer_print_header,
.print_line = blk_tracer_print_line,
.flags = &blk_tracer_flags,
+ .set_flag = blk_tracer_set_flag,
};
static struct trace_event trace_blk_event = {