From: David Miller <davem@davemloft.net>
To: tglx@linutronix.de
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
kaber@trash.net, peterz@infradead.org
Subject: Re: [patch 1/3] net: serialize hrtimer callback in sched_cbq
Date: Tue, 14 Jul 2009 09:00:55 -0700 (PDT) [thread overview]
Message-ID: <20090714.090055.56906831.davem@davemloft.net> (raw)
In-Reply-To: <alpine.LFD.2.00.0907141040350.2777@localhost.localdomain>
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 14 Jul 2009 10:55:14 +0200 (CEST)
> David,
>
> On Sun, 12 Jul 2009, David Miller wrote:
>
>> What should probably happen is that the hrtimer merely fires off work
>> at software interrupt context (perhaps a tasklet or similar), and that
>> software interrupt code take the qdisc's root lock throughout it's
>> execution.
>
> Sigh, I almost expected that the removal of the callback modes will
> fire back some day.
Well this makes hrtimers decidedly less useful for networking and we
have a ton of bugs right now, basically in every hrtimer used by the
networking currently.
The only way we can use them, as things currently stand, is as
triggers for softirq work.
Is it really that troublesome to provide this kind of facility
generically, rather than having various subsystems replicate such code
where they want to use hrtimers and are restricted to softirqs?
next prev parent reply other threads:[~2009-07-14 16:00 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-09 21:59 [patch 0/3] net: Sanitizing hrtimer usage in net/sched/sch_cbq.c Thomas Gleixner
2009-07-09 21:59 ` [patch 1/3] net: serialize hrtimer callback in sched_cbq Thomas Gleixner
2009-07-12 20:55 ` David Miller
2009-07-14 8:22 ` Patrick McHardy
2009-07-14 8:30 ` Peter Zijlstra
2009-07-14 16:01 ` David Miller
2009-07-14 8:55 ` Thomas Gleixner
2009-07-14 16:00 ` David Miller [this message]
2009-07-14 16:28 ` Peter Zijlstra
2009-07-14 16:42 ` Linus Torvalds
2009-07-17 12:14 ` Peter Zijlstra
2009-07-17 13:26 ` Oliver Hartkopp
2009-07-17 15:44 ` Linus Torvalds
2009-07-22 3:18 ` David Miller
2009-07-22 6:29 ` Peter Zijlstra
2009-07-22 12:28 ` [PATCH] softirq: tasklet_hrtimer Peter Zijlstra
2009-07-22 15:39 ` David Miller
2009-07-22 16:01 ` Linus Torvalds
2009-07-15 9:56 ` [patch 1/3] net: serialize hrtimer callback in sched_cbq Oliver Hartkopp
2009-07-09 21:59 ` [patch 2/3] net: sanitize hrtimer usage " Thomas Gleixner
2009-07-09 21:59 ` [patch 3/3] net: use HRTIMER_RESTART " Thomas Gleixner
2009-07-10 0:39 ` [patch 0/3] net: Sanitizing hrtimer usage in net/sched/sch_cbq.c David Miller
2009-07-12 20:57 ` David Miller
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