Commit a9b204d1 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

tcp: tsq: avoid one atomic in tcp_wfree()

Under high load, tcp_wfree() has an atomic operation trying
to schedule a tasklet over and over.

We can schedule it only if our per cpu list was empty.
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b223feb9
......@@ -880,6 +880,7 @@ void tcp_wfree(struct sk_buff *skb)
for (oval = READ_ONCE(tp->tsq_flags);; oval = nval) {
struct tsq_tasklet *tsq;
bool empty;
if (!(oval & TSQF_THROTTLED) || (oval & TSQF_QUEUED))
goto out;
......@@ -892,8 +893,10 @@ void tcp_wfree(struct sk_buff *skb)
/* queue this socket to tasklet queue */
local_irq_save(flags);
tsq = this_cpu_ptr(&tsq_tasklet);
empty = list_empty(&tsq->head);
list_add(&tp->tsq_node, &tsq->head);
tasklet_schedule(&tsq->tasklet);
if (empty)
tasklet_schedule(&tsq->tasklet);
local_irq_restore(flags);
return;
}
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment