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[S390] qdio: speed up multicast traffic on full HiperSocket queue 

If an asynchronous HiperSockets queue runs full, no further packet
can be sent. In this case the next initiative to give transmitted
skbs back to the stack is triggered only by a 10-seconds qdio timer.
This timer has been introduced for low multicast traffic scenarios
to guarantee freeing of skbs in a limited amount of time. For high
HiperSocket multicast traffic scenarios progress checking on the
outbound queue should be enforced by tasklet rescheduling.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Ursula Braun 2008-10-10 21:33:04 +02:00 committed by Martin Schwidefsky
parent f6bccf6954
commit 4bcb3a3718
2 changed files with 14 additions and 0 deletions
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8
drivers/s390/cio/qdio.h
View File

@ -16,6 +16,14 @@
#define QDIO_BUSY_BIT_GIVE_UP 2000000 /* 2 seconds = eternity */
#define QDIO_INPUT_THRESHOLD 500 /* 500 microseconds */
/*
* if an asynchronous HiperSockets queue runs full, the 10 seconds timer wait
* till next initiative to give transmitted skbs back to the stack is too long.
* Therefore polling is started in case of multicast queue is filled more
* than 50 percent.
*/
#define QDIO_IQDIO_POLL_LVL 65 /* HS multicast queue */
enum qdio_irq_states {
QDIO_IRQ_STATE_INACTIVE,
QDIO_IRQ_STATE_ESTABLISHED,

6
drivers/s390/cio/qdio_main.c
View File

@ -851,6 +851,12 @@ static void __qdio_outbound_processing(struct qdio_q *q)
if (queue_type(q) == QDIO_IQDIO_QFMT && !multicast_outbound(q))
return;
if ((queue_type(q) == QDIO_IQDIO_QFMT) &&
(atomic_read(&q->nr_buf_used)) > QDIO_IQDIO_POLL_LVL) {
tasklet_schedule(&q->tasklet);
return;
}
if (q->u.out.pci_out_enabled)
return;