When executing non-linked hashed work, io_worker_handle_work()
will lock-unlock wqe->lock to update hash, and then immediately
lock-unlock to get next work. Optimise this case and do
lock/unlock only once.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
fs/io-wq.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/fs/io-wq.c b/fs/io-wq.c
index 473af080470a..82e76011d409 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -474,11 +474,11 @@ static void io_worker_handle_work(struct io_worker *worker)
{
struct io_wqe *wqe = worker->wqe;
struct io_wq *wq = wqe->wq;
+ unsigned hash = -1U;
do {
struct io_wq_work *work;
- unsigned hash = -1U;
-
+get_next:
/*
* If we got some work, mark us as busy. If we didn't, but
* the list isn't empty, it means we stalled on hashed work.
@@ -524,9 +524,12 @@ static void io_worker_handle_work(struct io_worker *worker)
spin_lock_irq(&wqe->lock);
wqe->hash_map &= ~BIT_ULL(hash);
wqe->flags &= ~IO_WQE_FLAG_STALLED;
- spin_unlock_irq(&wqe->lock);
/* dependent work is not hashed */
hash = -1U;
+ /* skip unnecessary unlock-lock wqe->lock */
+ if (!work)
+ goto get_next;
+ spin_unlock_irq(&wqe->lock);
}
} while (work);
--
2.24.0
