From: Tejun Heo <tj@kernel.org>
metadata_wq serves on-stack work items from chunk_io(). Even if
multiple chunk_io() are simultaneously in progress, each is
independent and queued only once, so multithreaded workqueue can be
safely used.
Switch metadata_wq to multithread and flush the work item instead of
the workqueue in chunk_io().
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
---
drivers/md/dm-snap-persistent.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Index: linux-2.6.37/drivers/md/dm-snap-persistent.c
===================================================================
--- linux-2.6.37.orig/drivers/md/dm-snap-persistent.c
+++ linux-2.6.37/drivers/md/dm-snap-persistent.c
@@ -256,7 +256,7 @@ static int chunk_io(struct pstore *ps, v
*/
INIT_WORK_ONSTACK(&req.work, do_metadata);
queue_work(ps->metadata_wq, &req.work);
- flush_workqueue(ps->metadata_wq);
+ flush_work(&req.work);
return req.result;
}
@@ -818,7 +818,7 @@ static int persistent_ctr(struct dm_exce
atomic_set(&ps->pending_count, 0);
ps->callbacks = NULL;
- ps->metadata_wq = alloc_ordered_workqueue("ksnaphd", WQ_MEM_RECLAIM);
+ ps->metadata_wq = alloc_workqueue("ksnaphd", WQ_MEM_RECLAIM, 0);
if (!ps->metadata_wq) {
kfree(ps);
DMERR("couldn't start header metadata update thread");