From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jagdish Motwani <jagdish.motwani@elitecore.com>
Subject: performance degradation on kernel upgrade (due to commit ab0a9735e06914ce4d2a94ffa41497dbc142fe7f
 )
Date: Fri, 21 Sep 2012 19:17:56 +0530
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Recently i upgraded my kernel from 2.6.29.6 to 2.6.35.14.

After upgrading i got very poor performance on my postgre database.


My test.sql contains 10000 postgre insert query


Linux  2.6.29.6

time psql -U user -d database -f test.sql  > /dev/null
real    0m 7.23s
user    0m 0.38s
sys     0m 0.12s



Linux  2.6.35.14

# time psql -U user -d database -f test.sql  > /dev/null
real    1m 4.05s
user    0m 0.44s
sys    0m 0.12

I even tried Linux 3.5.4 and got similar results.

Using git bisect, i got commit ab0a9735e06914ce4d2a94ffa41497dbc142fe7f

Is it a behavior change or am i missing something? Are there any 
workarounds for this?


Regards,
Jagdish Motwan