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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 /block/blk-sysfs.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 'block/blk-sysfs.c')
| -rw-r--r-- | block/blk-sysfs.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 73f36beff5cd..8653d710b39e 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -387,16 +387,21 @@ struct kobj_type blk_queue_ktype = { int blk_register_queue(struct gendisk *disk) { int ret; + struct device *dev = disk_to_dev(disk); struct request_queue *q = disk->queue; if (WARN_ON(!q)) return -ENXIO; + ret = blk_trace_init_sysfs(dev); + if (ret) + return ret; + if (!q->request_fn) return 0; - ret = kobject_add(&q->kobj, kobject_get(&disk_to_dev(disk)->kobj), + ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue"); if (ret < 0) return ret; |