From: Joe Ceklosky <jfceklosky@gmail.com>
To: linux-kernel@vger.kernel.org
Subject: Possible 32-bit PAE kernel I/O slow down with 3.3.X
Date: Thu, 26 Apr 2012 21:53:44 -0400 [thread overview]
Message-ID: <4F99FC28.80504@gmail.com> (raw)
I have notice significant slow downs with disk I/O on a 32-bit PAE 3.3.X
kernels.
The test machine has 16GB memory, Intel i5 CPU, Intel
motherboard, and an Intel 160GB SSD. I copied 536M from one partition
on an SSD to another.
Yes, I should be using a 64bit kernel with 16GB!
Test 1:
kernel 3.3.2 32-bit PAE with kernel parm mem=3G
time cp -ra testdir/ /tmp
real 0m8.989s
user 0m0.094s
sys 0m1.080s
Test 2:
kernel 3.3.2 32-bit PAE
time cp -ra testdir/ /tmp
real 1m17.068s
user 0m0.173s
sys 0m2.149s
Also I tested kernel 3.2.16 32-bit PAE with no memory limits 16GB and it
was in line with test 1.
I can repeat and provide any debugging information if needed.
Thanks,
Joe Ceklosky
reply other threads:[~2012-04-27 1:53 UTC|newest]
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