There's no need to add self to waitqueue if doing a nonblock read. This could
help to avoid the spinlock contention.
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
drivers/net/macvtap.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 59e9605..2395062 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -845,7 +845,9 @@ static ssize_t macvtap_do_read(struct macvtap_queue *q,
struct kiocb *iocb,
ssize_t ret = 0;
while (len) {
- prepare_to_wait(sk_sleep(&q->sk), &wait, TASK_INTERRUPTIBLE);
+ if (!noblock)
+ prepare_to_wait(sk_sleep(&q->sk), &wait,
+ TASK_INTERRUPTIBLE);
/* Read frames from the queue */
skb = skb_dequeue(&q->sk.sk_receive_queue);
@@ -867,7 +869,8 @@ static ssize_t macvtap_do_read(struct macvtap_queue *q,
struct kiocb *iocb,
break;
}
- finish_wait(sk_sleep(&q->sk), &wait);
+ if (!noblock)
+ finish_wait(sk_sleep(&q->sk), &wait);
return ret;
}
--
1.7.1
--
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