diff options
| author | Chunwei Chen <[email protected]> | 2014-05-13 10:36:35 +0800 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2014-05-14 16:20:21 -0700 |
| commit | bc25c9325b0e5ced897b9820dad239539d561ec9 (patch) | |
| tree | dd7a9bf76d0f0aa232ce2eaaa61c083a5238edc9 /module/zfs/vdev_file.c | |
| parent | 2c33b9127569ad62b4cfe7dd4f651ceeee3d005c (diff) | |
Use a dedicated taskq for vdev_file
Originally, vdev_file used system_taskq. This would cause a deadlock,
especially on system with few CPUs. The reason is that the prefetcher
threads, which are on system_taskq, will sometimes be blocked waiting
for I/O to finish. If the prefetcher threads consume all the tasks in
system_taskq, the I/O cannot be served and thus results in a deadlock.
We fix this by creating a dedicated vdev_file_taskq for vdev_file I/O.
Signed-off-by: Chunwei Chen <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #2270
Diffstat (limited to 'module/zfs/vdev_file.c')
| -rw-r--r-- | module/zfs/vdev_file.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/module/zfs/vdev_file.c b/module/zfs/vdev_file.c index 858582aca..330580224 100644 --- a/module/zfs/vdev_file.c +++ b/module/zfs/vdev_file.c @@ -36,6 +36,8 @@ * Virtual device vector for files. */ +static taskq_t *vdev_file_taskq; + static void vdev_file_hold(vdev_t *vd) { @@ -184,7 +186,7 @@ vdev_file_io_start(zio_t *zio) return (ZIO_PIPELINE_CONTINUE); } - VERIFY3U(taskq_dispatch(system_taskq, vdev_file_io_strategy, zio, + VERIFY3U(taskq_dispatch(vdev_file_taskq, vdev_file_io_strategy, zio, TQ_PUSHPAGE), !=, 0); return (ZIO_PIPELINE_STOP); @@ -209,6 +211,21 @@ vdev_ops_t vdev_file_ops = { B_TRUE /* leaf vdev */ }; +void +vdev_file_init(void) +{ + vdev_file_taskq = taskq_create("vdev_file_taskq", 100, minclsyspri, + max_ncpus, INT_MAX, TASKQ_PREPOPULATE | TASKQ_THREADS_CPU_PCT); + + VERIFY(vdev_file_taskq); +} + +void +vdev_file_fini(void) +{ + taskq_destroy(vdev_file_taskq); +} + /* * From userland we access disks just like files. */ |