lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <4799C8E8.9060501@ifi.uio.no>
Date:	Fri, 25 Jan 2008 12:32:56 +0100
From:	Asbjorn Sannes <asbjorsa@....uio.no>
To:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Unpredictable performance

Hi,

I am experiencing unpredictable results with the following test
without other processes running (exception is udev, I believe):
cd /usr/src/test
tar -jxf ../linux-2.6.22.12
cp ../working-config linux-2.6.22.12/.config
cd linux-2.6.22.12
make oldconfig
time make -j3 > /dev/null # This is what I note down as a "test" result
cd /usr/src ; umount /usr/src/test ; mkfs.ext3 /dev/cc/test
and then reboot

The kernel is booted with the parameter mem=81920000

For 2.6.23.14 the results vary from (real time) 33m30.551s to 45m32.703s
(30 runs)
For 2.6.23.14 with nop i/o scheduler from 29m8.827s to 55m36.744s (24 runs)
For 2.6.22.14 also varied a lot.. but, lost results :(
For 2.6.20.21 only vary from 34m32.054s to 38m1.928s (10 runs)

Any idea of what can cause this? I have tried to make the runs as equal
as possible, rebooting between each run.. i/o scheduler is cfq as default.

sys and user time only varies a couple of seconds.. and the order of
when it is "fast" and when it is "slow" is completly random, but it
seems that the results are mostly concentrated around the mean.

--
Asbjørn Sannes

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ