Bug 196462

Summary: SPECsfs running on FC5 and later experiencing tons of fh_update: messages and capping performance
Product: [Fedora] Fedora Reporter: Barry Marson <bmarson>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED RAWHIDE QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 6CC: bmarson, wtogami
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Hardware: x86_64   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2006-09-25 19:37:29 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Barry Marson 2006-06-23 14:45:49 UTC
Description of problem:

Runs of SPECsfs NFS benchmark are seeing a high number of ...

    kernel: fh_update: dir_ent.00015/file_en.00454 already up-to-date!

type messages in dmesg, and /var/log/messages.  According to Steve Dickson, this
code path is normal, especially with an elevated number of nfsd threads.  We run
with upwards of 256 threads depending on config and filesystem.  Yet the logging
of these of these messages, which I believe is synchronouse kills the benchmarks
performance.

Examining the messages file, I have determined we do about 10 messages for every
1000 ops requested.  The data I analyzed showed 100 messages/sec at 10000
Ops/sec.  We are typically testing with 3 times that.

How do we get this informative message shut off or disabled in normal operation ?

Thanks,

Barry

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

Tested with FC5-GOLD and verified same behavior in 2.6.16-1.2289_FC6

How reproducible:

Always and with ext3 and xfs (so far).

Steps to Reproduce:
1. Run sfs benchmark with at least nfsd 64 threads
2.
3.
  
Actual results:


Expected results:


Additional info:

Comment 1 Eric Sandeen 2006-09-25 19:37:29 UTC
This is fixed upstream since late June:

http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=4c9608b2f2f51e84eba72f4bf061d360259ce656

[PATCH] knfsd: remove noise about filehandle being uptodate

There is a perfectly valid situation where fh_update gets called on an already
uptodate filehandle - in nfsd_create_v3 where a CREATE_UNCHECKED finds an
existing file and wants to just set the size.

...

-out_uptodate:
- printk(KERN_ERR "fh_update: %s/%s already up-to-date!\n",
- dentry->d_parent->d_name.name, dentry->d_name.name);
- goto out;

and it seems to be fine in FC6 now.  Not sure about FC5 but since this bug is
against FC6 I think it's fixed.