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authorArnaldo Carvalho de Melo2009-01-26 12:00:40 -0600
committerIngo Molnar2009-01-27 07:30:36 -0600
commit32c0bd9624115041cfec31c0436995418083090a (patch)
tree833dfe1e19338721d1043a2ecfa96a40703c0749 /block/Kconfig
parent157f9c00e88529ed84bd7d581a40d411e5414cf0 (diff)
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blktrace: the ftrace interface needs CONFIG_TRACING
Impact: build fix Also mention in the help text that blktrace now can be used using the ftrace interface. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'block/Kconfig')
-rw-r--r--block/Kconfig8
1 files changed, 8 insertions, 0 deletions
diff --git a/block/Kconfig b/block/Kconfig
index 0cbb3b88b59..7cdaa1d7225 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -50,6 +50,8 @@ config BLK_DEV_IO_TRACE
50 select RELAY 50 select RELAY
51 select DEBUG_FS 51 select DEBUG_FS
52 select TRACEPOINTS 52 select TRACEPOINTS
53 select TRACING
54 select STACKTRACE
53 help 55 help
54 Say Y here if you want to be able to trace the block layer actions 56 Say Y here if you want to be able to trace the block layer actions
55 on a given queue. Tracing allows you to see any traffic happening 57 on a given queue. Tracing allows you to see any traffic happening
@@ -58,6 +60,12 @@ config BLK_DEV_IO_TRACE
58 60
59 git://git.kernel.dk/blktrace.git 61 git://git.kernel.dk/blktrace.git
60 62
63 Tracing also is possible using the ftrace interface, e.g.:
64
65 echo 1 > /sys/block/sda/sda1/trace/enable
66 echo blk > /sys/kernel/debug/tracing/current_tracer
67 cat /sys/kernel/debug/tracing/trace_pipe
68
61 If unsure, say N. 69 If unsure, say N.
62 70
63config BLK_DEV_BSG 71config BLK_DEV_BSG