Re: Voluntary Kernel Preemption Patch

Con Kolivas
2004-07-13T00:24:45Z

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Andrew Morton writes:

> Paul Davis <paul@linuxaudiosystems.com> wrote:
>>
>> >resierfs: yes, it's a problem. I "fixed" it multiple times in 2.4, but the
>> >fixes ended up breaking the fs in subtle ways and I eventually gave up.
>>
>> andrew, this is really helpful. should we conclude that until some
>> announcement from reiser that they have addressed this, the reiserfs
>> should be avoided on low latency systems?
>>
>
> It seems that way, yes. I do not know how common the holdoffs are in real
> life. It would be interesting if there was a user report that switching
> from reiserfs to ext2/ext3 actually made a difference - this would tell us
> that it is indeed a real-world problem.
>
> Note that this info because available because someone set
> /proc/asound/*/*/xrun_debug. We need more people doing that

Can I just point out that the reiserfs3.6 delays that I originally reported
with the preempt threshhold test did not come up once the patch was fixed. I
have my preempt threshold set at 1ms and did not see one single reiserfs
dump in my syslog. ie I don't think I am personally seeing any significant
reiserfs3.6 latencies.

Cheers,
Con

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