ext3 reservation seems to cause major slowdown in synctest in 2.6.10-rc2 vs 2.6.9

From: Yusuf Goolamabbas
Date: Mon Nov 15 2004 - 01:34:54 EST

I have a P3-500 box /384 MB ram and 2 scsi disks (sda and sdb).
OS is on sda and test partions is on sdb
aic7xxx driver
Using anticipatory schedulor with a tag_depth of 4 (this is set via
options aic7xxx aic7xxx=global_tag_depth:4

/dev/sdb1 is created with ext3 and htree is enabled. Mounted as /htree

synctest obtained from here (synctest tries to simulate an MTA


I run the following commands on both 2.6.9 and 2.6.10-rc2

/usr/bin/time -p ./synctest -fu -t 100 -p1 -n1 /htree/nfsexport

timing results


real 57.35
user 1.37
sys 14.26


real 86.83
user 1.32
sys 14.02

Mounting with noreservation gives the following numbers

real 58.77
user 1.46
sys 14.48

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