From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: David Miller <davem@davemloft.net>
Cc: mkl@pengutronix.de, linux-rt-users@vger.kernel.org,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
kernel@pengutronix.de
Subject: Re: [PATCH] net: sched: dev_deactivate_many(): use msleep(1) instead of yield() to wait for outstanding qdisc_run calls
Date: Fri, 07 Mar 2014 05:26:37 +0100 [thread overview]
Message-ID: <1394166397.5056.40.camel@marge.simpson.net> (raw)
In-Reply-To: <20140306.160622.59358366688518505.davem@davemloft.net>
On Thu, 2014-03-06 at 16:06 -0500, David Miller wrote:
> From: Marc Kleine-Budde <mkl@pengutronix.de>
> Date: Wed, 5 Mar 2014 00:49:47 +0100
>
> > @@ -839,7 +839,7 @@ void dev_deactivate_many(struct list_head *head)
> > /* Wait for outstanding qdisc_run calls. */
> > list_for_each_entry(dev, head, unreg_list)
> > while (some_qdisc_is_busy(dev))
> > - yield();
> > + msleep(1)
> > }
>
> I don't understand this.
>
> yield() should really _mean_ yield.
It does, but yield() semantics make it useless for what you want to do..
and pretty much undefined for anything other than SCHED_FIFO. If you
really want to give up the CPU to any old body, you have to sleep.
-Mike
next prev parent reply other threads:[~2014-03-07 4:26 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-04 23:49 [PATCH] net: sched: dev_deactivate_many(): use msleep(1) instead of yield() to wait for outstanding qdisc_run calls Marc Kleine-Budde
2014-03-06 21:06 ` David Miller
2014-03-06 21:39 ` Marc Kleine-Budde
2014-03-07 15:47 ` Sebastian Andrzej Siewior
2014-03-07 4:26 ` Mike Galbraith [this message]
2014-03-09 19:09 ` Ben Hutchings
2014-03-09 22:53 ` David Miller
2014-03-09 23:17 ` Ben Hutchings
2014-03-09 23:28 ` David Lang
2014-03-10 0:07 ` Stanislav Meduna
2014-03-31 21:49 ` [PATCH] net: sched: dev_deactivate_many(): use msleep(1) instead of yield() to wait for outstanding qdisc_run callsb Thomas Gleixner
2014-04-02 11:07 ` Peter Zijlstra
2014-04-02 11:17 ` Eric Dumazet
2014-04-04 15:19 ` Peter Zijlstra
2014-04-04 15:26 ` David Miller
2014-04-07 11:19 ` Peter Zijlstra
2014-04-04 15:28 ` David Miller
2014-04-07 11:24 ` Peter Zijlstra
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