* qdisc_restart locking bug?
@ 2002-11-15 19:01 Jeff Garzik
2002-11-15 21:41 ` kuznet
0 siblings, 1 reply; 2+ messages in thread
From: Jeff Garzik @ 2002-11-15 19:01 UTC (permalink / raw)
To: netdev; +Cc: davem, kuznet
When qdisc_restart() is called from qdisc_run(), dev->queue_lock is
obtained via spin_lock_bh().
When dev->hard_start_xmit() is called from qdisc_restart(),
dev->queue_lock is dropped, and then re-acquired using only spin_lock().
So, doesn't qdisc_restart need s/spin_lock/spin_lock_bh/ for
dev->queue_lock?
When looking at the dev_queue_xmit -> qdisc_run -> qdisc_restart call
path, it seems so to me.
Jeff
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: qdisc_restart locking bug?
2002-11-15 19:01 qdisc_restart locking bug? Jeff Garzik
@ 2002-11-15 21:41 ` kuznet
0 siblings, 0 replies; 2+ messages in thread
From: kuznet @ 2002-11-15 21:41 UTC (permalink / raw)
To: Jeff Garzik; +Cc: netdev, davem
Hello!
> When dev->hard_start_xmit() is called from qdisc_restart(),
> dev->queue_lock is dropped,
Using spin_unlock(). softirqs are not enabled.
> and then re-acquired using only spin_lock().
Yes.
> So, doesn't qdisc_restart need s/spin_lock/spin_lock_bh/ for
> dev->queue_lock?
It need not.
Alexey
^ permalink raw reply [flat|nested] 2+ messages in thread
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2002-11-15 19:01 qdisc_restart locking bug? Jeff Garzik
2002-11-15 21:41 ` kuznet
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