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| author | Li Zefan <lizf@cn.fujitsu.com> | 2009-04-14 14:00:05 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-16 10:10:59 +0200 |
| commit | 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82 (patch) | |
| tree | fd5917f144ec820b933795bedd7eddea96bee374 /kernel/trace/blktrace.c | |
| parent | 9908c30997b8a73c95f836170b9998dae9aa3f4a (diff) | |
| download | lwn-1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.tar.gz lwn-1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.zip | |
blktrace: add trace/ to /sys/block/sda
Impact: allow ftrace-plugin blktrace to trace device-mapper devices
To trace a single partition:
# echo 1 > /sys/block/sda/sda1/enable
To trace the whole sda instead:
# echo 1 > /sys/block/sda/enable
Thus we also fix an issue reported by Ted, that ftrace-plugin blktrace
can't be used to trace device-mapper devices.
Now:
# echo 1 > /sys/block/dm-0/trace/enable
echo: write error: No such device or address
# mount -t ext4 /dev/dm-0 /mnt
# echo 1 > /sys/block/dm-0/trace/enable
# echo blk > /debug/tracing/current_tracer
Reported-by: Theodore Tso <tytso@mit.edu>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Shawn Du <duyuyang@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
LKML-Reference: <49E42665.6020506@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/blktrace.c')
| -rw-r--r-- | kernel/trace/blktrace.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index d10989880520..8e7c5da3a3e6 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1644,3 +1644,8 @@ out: return ret ? ret : count; } +int blk_trace_init_sysfs(struct device *dev) +{ + return sysfs_create_group(&dev->kobj, &blk_trace_attr_group); +} + |