Messages in this thread | | | Date | Fri, 18 Jun 2010 00:31:27 -0700 | From | Andrew Morton <> | Subject | Re: Overview of concurrency managed workqueue |
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On Fri, 18 Jun 2010 09:16:15 +0200 Tejun Heo <tj@kernel.org> wrote:
> On 06/18/2010 01:16 AM, Andrew Morton wrote: > > On Thu, 17 Jun 2010 08:01:06 -0400 > > Andy Walls <awalls@md.metrocast.net> wrote: > > > >> I'm going to agree with Tejun, that tweaking worker thread priorities > >> seems like an odd thing, since they are meant to handle deferable > >> actions - things that can be put off until later. > > > > Disagree. If you're in an interrupt handler and have some work which > > you want done in process context and you want it done RIGHT NOW then > > handing that work off to a realtime-policy worker thread is a fine way of > > doing that. > > In that case, the right thing to do would be using threaded interrupt > handler. It's not only easier but also provide enough context such > that RT kernel can do the right thing.
Nope. Consider a simple byte-at-a-time rx handler. The ISR grabs the byte, stashes it away, bangs on the hardware a bit then signals userspace to promptly start processing that byte. Very simple, legitimate and a valid thing to do.
Also the "interrupt" code might be running from a timer handler. Or it might just be in process context, buried in a forest of locks and wants to punt further processing into a separate process.
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