From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Chris Friesen" <cfriesen@nortel.com>
Subject: Re: question about softirqs
Date: Wed, 13 May 2009 13:44:59 -0600
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Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>, netdev@vger.kernel.org,
	Ingo Molnar <mingo@elte.hu>,
	Steven Rostedt <rostedt@goodmis.org>, linuxppc-dev@ozlabs.org,
	paulus@samba.org, Thomas Gleixner <tglx@linutronix.de>,
	David Miller <davem@davemloft.net>
To: Andi Kleen <andi@firstfloor.org>
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Andi Kleen wrote:
> On Wed, May 13, 2009 at 01:04:09PM -0600, Chris Friesen wrote:
>> Andi Kleen wrote:
>>
>>> network packets are normally processed by the network packet interrupt's
>>> softirq or alternatively in the NAPI poll loop.
>> If we have a high priority task, ksoftirqd may not get a chance to run.
> 
> In this case the next interrupt will also process them. It will just
> go more slowly because interrupts limit the work compared to ksoftirqd.

I realize that they will eventually get processed.  My point is that the
documentation (in-kernel, online, and in various books) says that
softirqs will be processed _on the return from a syscall_.  As we all
agree, this is not necessarily the case.

Chris