Re: nfs slowdown since 2.5.4

[Matthias Welk <welk@fokus.gmd.de>]

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On Tuesday 04 June 2002 14:23, Trond Myklebust wrote:
> >>>>> " " == Matthias Welk <welk@fokus.gmd.de> writes:
>      > Hi, since 2.5.4 I noticed a big slowdown in nfs.  It seems that
>      > this is related to the changes in the nfs-lookup code, because
>      > now most traffic via nfs is for lookup- and getattr-calls as
>      > you can see in the attached tcpdump log.  I'v also attached a
>      > log of nfsstat, which shows this problem too.
>
> Tough... Those extra checks are needed in order to ensure data cache
> correctness on file open().
>
> If you think you don't need them because the files that you are
> reading are known never to change on the server, you can try mounting
> with the 'nocto' mount option.
>

I tried again with the 'nocto' mount option, although I can't be sure that the 
files will not change on the server, but the behaviour didn't change :-(

To get more info about this problem I compared the compile time and the nfs 
traffic between 2.4.18-4 and 2.5.20 on a RedHat 7.3 system.
The sources (mosfet-liquid0.9.5.tar.gz - KDE style) were located on the local 
disc and the libraries were linked over nfs.
The results attached to this mail show the big difference !

I hope you can do anything with it.

Greetings, Matthias.
-- 
---------------------------------------------------------------
From: Matthias Welk                   office:  +49-30-3463-7272
      FHG Fokus                       mobile:  +49-179- 1144752
      Kaiserin-Augusta-Allee 31       fax   :  +49-30-3463-8672
      10589 Berlin		      email : welk@fokus.fhg.de
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#time to build on a RedHat 7.3 system with 2.4.18-4

real	1m1.301s
user	0m50.920s
sys	0m8.390s

lookup:		2820
getattr:	22
readdir:	96
frag:		66

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#time to build on a RedHat 7.3 system with 2.5.20

real    1m48.509s
user    0m51.320s
sys     0m12.790s


lookup:		287582
getattr:	2546
readdir:	1958
frag:		8465