[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20070717061458.GB1640@ff.dom.local>
Date: Tue, 17 Jul 2007 08:14:58 +0200
From: Jarek Poplawski <jarkao2@...pl>
To: Ingo Molnar <mingo@...e.hu>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>,
linux-kernel@...r.kernel.org, olaf.kirch@...cle.com,
davem@...emloft.net
Subject: Re: [patch] revert: [NET]: Fix races in net_rx_action vs netpoll
On Tue, Jul 17, 2007 at 07:46:39AM +0200, Jarek Poplawski wrote:
...
> > static void net_rx_action(struct softirq_action *h)
> > {
> > struct softnet_data *queue = &__get_cpu_var(softnet_data);
> > unsigned long start_time = jiffies;
> > int budget = netdev_budget;
> > void *have;
> >
> > local_irq_disable();
> >
> > while (!list_empty(&queue->poll_list)) {
> > struct net_device *dev;
> >
> > if (budget <= 0 || jiffies - start_time > 1)
> > goto softnet_break;
> >
> > local_irq_enable();
> >
> > dev = list_entry(queue->poll_list.next,
> > struct net_device, poll_list);
> > have = netpoll_poll_lock(dev);
> >
> > if (dev->quota <= 0 || dev->poll(dev, &budget)) {
>
> If after poll_napi dev->quota <= 0 dev->poll is not run and
> __LINK_STATE_RX_SCHED bit (plus dev->poll_list) stays uncleared.
Or, more precisely dev->poll_list will be cleared just after this,
and net_rx_action returns with __LINK_STATE_RX_SCHED bit set.
Jarek P.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists