Messages in this thread | | | Date | Tue, 09 Dec 2008 09:07:01 +0100 | From | Oliver Hartkopp <> | Subject | Re: [RFC PATCH] hrtimer: removing all ur callback modes |
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Peter Zijlstra wrote: > On Sun, 2008-12-07 at 13:59 +0100, Oliver Hartkopp wrote: > >> Oliver Hartkopp wrote: >> >>> Peter Zijlstra wrote: >>> >>>> On Tue, 2008-11-25 at 12:43 +0100, Peter Zijlstra wrote: >>>> >>>> >>>>> Hi, >>>>> >>>>> This is an attempt at removing some of the hrtimer complexity by >>>>> reducing the number of callback modes to 1. >>>>> >>>>> This means that all hrtimer callback functions will be ran from >>>>> HARD-irq >>>>> context. >>>>> >>>>> >> Hi Peter, >> >> i ran a heavy load test, which get's (reproducible) the attached outputs ... >> >> Maybe it's not that good to define the hrtimer context to be always >> hard-irq. >> > > Thing is, this 'cleanup' removes quite a bit of complexity from the core > hrtimer code, and afaict your bit is the only thing that cannot seem to > cope. So I'd rather look at fixing your site than re-introduce softirqs > to hrtimers. > >
I wouldn't be that sure that all the other sites can cope with it as i only detected the problems with my code under heavy load ...
>> Any idea? >> > > What are the timing constraints of your problem? - I assume they are not > too aggressive, otherwise you'd not be able to run from softirq, could > you run from keventd? >
I browsed some code that's using hrtimers and found some hopefully good example in drivers/s390/crypto/ap_bus.c : They are using the hrtimer to schedule a tasklet which is running in soft-irq context:
http://lxr.linux.no/linux+v2.6.27.8/drivers/s390/crypto/ap_bus.c#L1150
This could also be the correct approach for my sock_queue_rcv_skb() problem, right?
Regards, Oliver
ps. What is the intended release for this hrtimer cleanup? 2.6.29?
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