Bug 67543 - NFS attribute caching bug
NFS attribute caching bug
Product: Red Hat Linux
Classification: Retired
Component: kernel (Show other bugs)
i386 Linux
medium Severity medium
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Assigned To: Steve Dickson
Brian Brock
Depends On:
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Reported: 2002-06-27 00:25 EDT by Yusuf Goolamabbas
Modified: 2007-04-18 12:43 EDT (History)
2 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Last Closed: 2004-01-12 07:47:08 EST
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Description Yusuf Goolamabbas 2002-06-27 00:25:23 EDT
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.1a+) Gecko/20020625

Description of problem:
The latest redhat kernel release 2.4.18-5 has a lot of NFS patches,
According to NFS client maintainer, Trond Myklebust these seem to
cause excessive GETATTR calls

He has published a patch which fixes this


Note 100% sure if you need to incorporate this

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. upgrade to 2.4.18-5

Additional info:
Comment 1 Jay Hilliard 2003-03-08 03:42:30 EST
This bug, which appears to continue even in 2.4.18-24.7.x is a showstopper for
us.  Performance in Maya suffers greatly.
Comment 2 Steve Dickson 2003-03-09 14:48:47 EST
This patch is already in RH9 so I'm not sure 
what (if anything) I should do with this. 
Comment 3 Jay Hilliard 2003-03-10 19:15:04 EST
RH9?  Will it not be available in a future kernel for 7.3 or 8.0?  Or are you
referring to PHOEBE?
Comment 4 Jay Hilliard 2003-04-18 19:49:57 EDT
excessive GETATTR calls continue in RH7.3, RH8, and even RH9.

What is the likelihood of Tronds patches making it into an errata kernel?
Comment 5 Yusuf Goolamabbas 2003-04-28 10:51:19 EDT
Jay, The latest rawhide kernel changelog mentions some NFS performance patches
being included. Maybe Steve can comment upon those
Comment 6 Bill Heiden 2003-07-11 21:44:43 EDT
 We are also having the same performance problems with maya under both 7.2
(2.4.18-26.7 kernel), 9.0, and the base installation of the v2.1 enterprise WS
kernel.  We've also tried installing Tron's patches with no luck.  However, one
interesting thing is the performance problem only appears with NFS3 in the
enterprise release.  Under a base enterprise installation, setting the nfs
mounts to use NFS2 will result in normal performance.  I've set the mounts to
NFS2 under 2.4.18-26.7 and see the same performance problems.  This is a highly
critical bug for us and is totally impacting our work.
Comment 7 Steve Dickson 2003-07-22 15:58:07 EDT
When you say performance issues what exactly do you mean?
What test suite or commands are you running that
show this poor performance
Comment 8 Jay Hilliard 2003-07-22 20:53:07 EDT
An example of how we can find the problem:

### wake up automounter and mount /data/ada14

### stat 3 files 10000 times
undef $done;
while (! $done) {
   @blah = stat("/data/ada14/tech/blah");
   @blah2 = stat("/data/ada14/tech/blah2");
   @blah3 = stat("/data/ada14/tech/blah3");
   if ($go == 10000) {$done = "yes"};

print "looped $go times\n";

### NOTE:  automounter mounts /data/ada14 with these options
### -intr --timeout=1800,nfsvers=3,tcp,rsize=32768,wsize=32768
### /data/ada14 is a T3 Array on a Sun V880 with Veritas Filesystem
### Similar results occur when the file server is an SGI Irix 6.5.13 with XLV 
and xfs filesystem.
### If attributes are cached, this test completes almost instantly, if it 
doesn't cache attributes
### of each stat, then it takes a long time to complete.
Comment 9 Bill Heiden 2003-07-22 21:14:21 EDT
 Jay's example perfectly illustrates the problem.  And as another data point, 
this problem exists in the enterprise v2.1 base distro (2.4.9-e.12)with nfs3 
mounts, but not with nfs2 mounts.  However, with an upgrade to 2.4.9-e.25, the 
problem no longer exists for either nfs2 or nfs3.

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