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authorPekka Paalanen <pq@iki.fi>2008-09-16 15:06:42 -0400
committerIngo Molnar <mingo@elte.hu>2008-10-14 04:37:20 -0400
commit5bf9a1ee350a10feb94107de32a203d81fbbe706 (patch)
treeac6b11aaa35194aed9fe9f1403c9542d070d0c62 /Documentation/tracers/mmiotrace.txt
parent4427414170a63331a9cc36b9598502c5cdfe453b (diff)
ftrace: inject markers via trace_marker file
Allow a user to inject a marker (TRACE_PRINT entry) into the trace ring buffer. The related file operations are derived from code by Frédéric Weisbecker <fweisbec@gmail.com>. Signed-off-by: Pekka Paalanen <pq@iki.fi> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/tracers/mmiotrace.txt')
-rw-r--r--Documentation/tracers/mmiotrace.txt5
1 files changed, 2 insertions, 3 deletions
diff --git a/Documentation/tracers/mmiotrace.txt b/Documentation/tracers/mmiotrace.txt
index a4afb560a45b..5bbbe2096223 100644
--- a/Documentation/tracers/mmiotrace.txt
+++ b/Documentation/tracers/mmiotrace.txt
@@ -36,7 +36,7 @@ $ mount -t debugfs debugfs /debug
36$ echo mmiotrace > /debug/tracing/current_tracer 36$ echo mmiotrace > /debug/tracing/current_tracer
37$ cat /debug/tracing/trace_pipe > mydump.txt & 37$ cat /debug/tracing/trace_pipe > mydump.txt &
38Start X or whatever. 38Start X or whatever.
39$ echo "X is up" > /debug/tracing/marker 39$ echo "X is up" > /debug/tracing/trace_marker
40$ echo none > /debug/tracing/current_tracer 40$ echo none > /debug/tracing/current_tracer
41Check for lost events. 41Check for lost events.
42 42
@@ -59,9 +59,8 @@ The 'cat' process should stay running (sleeping) in the background.
59Load the driver you want to trace and use it. Mmiotrace will only catch MMIO 59Load the driver you want to trace and use it. Mmiotrace will only catch MMIO
60accesses to areas that are ioremapped while mmiotrace is active. 60accesses to areas that are ioremapped while mmiotrace is active.
61 61
62[Unimplemented feature:]
63During tracing you can place comments (markers) into the trace by 62During tracing you can place comments (markers) into the trace by
64$ echo "X is up" > /debug/tracing/marker 63$ echo "X is up" > /debug/tracing/trace_marker
65This makes it easier to see which part of the (huge) trace corresponds to 64This makes it easier to see which part of the (huge) trace corresponds to
66which action. It is recommended to place descriptive markers about what you 65which action. It is recommended to place descriptive markers about what you
67do. 66do.