Re: [linux-audio-dev] Re: [announce] [patch] Voluntary Kernel Preemption Patch

Randy.Dunlap
2004-07-13T23:55:36Z

On Tue, 13 Jul 2004 18:40:30 -0400 Bill Davidsen wrote:

| Andrew Morton wrote:
| > Lee Revell <rlrevell@joe-job.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.
| >> >
| >>
| >> Interesting. There is an overwhelming consensus amongst Linux audio
| >> folks that you should use reiserfs for low latency work.
| >
| >
| > It seems to be misplaced. A simple make-a-zillion-teeny-files test here
| > exhibits a 14 millisecond holdoff.
| >
| >
| >> Should I try ext3?
| >
| >
| > ext3 is certainly better than that, but still has a couple of potential
| > problem spots. ext2 is probably the best at this time.
|
| Does anyone have any data points on XFS in this regard? I agree that
| ext2 is faster than ext3, and ext3 probably has lower latency than
| reiser3, but I have no info at all on XFS. My JFS experience is all on
| AIX, as well, so if anyone has that info it might be interesting as well.

Yes, but not recent. I did lots of journaling-fs testing and
workloads on 2.4.19-pre7 for LinuxWorld Aug. 2004.
Presentation is here:
http://developer.osdl.org/rddunlap/journal_fs/lwe-jgfs.pdf

Simplified summary:

XFS fared well on (large) sequential IO workloads.
And of course, none of the journaling fs-es beat ext2, but
XFS came the closest.

At the time of that presentation, JFS was very slow. The JFS team
was working on correctness/robustness only, not performance.
I don't know the status of that today.
It's somewhat of a shame, because on paper JFS looks like a great
filesystem (IMO).

--
~Randy