Subject: Re: [linux-audio-dev] low-latency patch
From: Jörn Nettingsmeier (nettings_AT_folkwang.uni-essen.de)
Date: Wed Jul 12 2000 - 21:58:11 EEST
andrew, you're my hero.
thanks for the kernel-howto !
Andrew Morton wrote:
>
> This is pretty much "it". I ran it for six hours on a "typical
> desktop", running X, netscape, Apache, StarOffice, imapd, ftpd,
> sendmail, fetchmail, etc and the worst-case latency was 3-4 millisecs:
>
> 0-1 millisecs: 99.999%
> 1-2 0.0004%
> 2-3 0.00009%
> 3-4 0.0005%
>
yeah. this is absolutely good enough for our current needs.
(except if somebody is being creative again :)
> Yes, there are probably still ways it can be tripped up, but there's no
> point in addressing these unless someone can demonstrate a problem which
> doesn't have an acceptable workaround. I can't, apart from waking up
> kswapd.
>
> There are now nine rescheduling points which handle:
>
> sys_unlink()
> sys_msync()
> sys_read()
> sys_madvise(MADV_DONTNEED)
> sys_write()
> sys_sync()
> sys_munmap()
> sys_exit() (__exit_mm)
not that i understand any details, but this should be far from
"random hacks all over the kernel".
> Filesystems other than ext2 and NFS client have not been tested.
oh-oh. i have reiserfs on /usr and /var (suse bigot !).
i will try it anyway. did you patch any ext2-specific stuff, or is
it all in common code on the VFS layer ? (excuse the dumbness of my
question, but even if i UTSL, it wouldn't help much !)
plus i have a nfs client. let's see what happens.
btw: i haven't been able to compile 2.4-test3 out of the box.
will try again with the latest pre-patches.
regards,
jörn
-- Jörn Nettingsmeier Kurfürstenstr. 49 45138 Essen, Germany http://www.folkwang.uni-essen.de/~nettings/
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