Bug 245776 - Purge count math is not correct in glock trimming patch
Summary: Purge count math is not correct in glock trimming patch
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Cluster Suite
Classification: Retired
Component: GFS-kernel
Version: 4
Hardware: All
OS: Linux
high
medium
Target Milestone: ---
Assignee: Wendy Cheng
QA Contact: GFS Bugs
URL:
Whiteboard:
Depends On:
Blocks: 247650
TreeView+ depends on / blocked
 
Reported: 2007-06-26 17:23 UTC by Wendy Cheng
Modified: 2010-01-12 03:18 UTC (History)
1 user (show)

Fixed In Version: RHBA-2007-0998
Clone Of:
Environment:
Last Closed: 2007-11-21 21:14:29 UTC
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2007:0998 0 normal SHIPPED_LIVE GFS-kernel bug fix update 2007-11-29 14:35:09 UTC

Description Wendy Cheng 2007-06-26 17:23:25 UTC
Description of problem:
Previous CVS check-in did a last minute change with the way purge count 
was calculated. The intention was to trim glocks evenly across all the 
hash buckets and apparently the size of hash array was overlooked. It 
ends up with zero trimming count most of the time. This virtually makes 
glock trimming patch a void feature. Need to fix this asap. 

Version-Release number of selected component (if applicable):
RHEL 4.5

How reproducible:
Most of the time unless accumulated glock count is well above 8k. 

Steps to Reproduce:
1. Untar a tar file with lots of small files
2. Issue gfs_tool lockdump to see the glock count.
3. Issue "gfs_tool settune <mnt> glock_purge 100" to trim the glock
  
Actual results:
Glock count could stay constant for the duration of the mount time.

Expected results:
Glock count should go down gradually (around 6~10 minutes)

Additional info:

Comment 2 Wendy Cheng 2007-06-26 17:42:30 UTC
Thanks to Barry Marson. The regression was found in his SPECsfs runs. 

Comment 4 Wendy Cheng 2007-06-26 20:40:05 UTC
Checked into RHEL4 and RHEL4.5 CVS branches.

Comment 9 errata-xmlrpc 2007-11-21 21:14:29 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2007-0998.html



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