lkml.org 
[lkml]   [2008]   [Dec]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC PATCH] hrtimer: removing all ur callback modes
    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?




    \
     
     \ /
      Last update: 2008-12-09 09:11    [W:3.652 / U:0.040 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site