Following is the bugzilla that was opened against this problem. <a href="http://bugzilla.kernel.org/show_bug.cgi?id=10378">http://bugzilla.kernel.org/show_bug.cgi?id=10378</a> Since I wasn't able to reproduce it on a server machine again, it was later closed. If you think it is the same issue, please feel free to re-open it. Ritesh <div class="gmail_quote">On Mon, Jun 2, 2008 at 6:01 PM, Yan Li <<a href="mailto:elliot.li.tech@gmail.com">elliot.li.tech@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi Milan, <div class="Ih2E3d"> On Mon, Jun 02, 2008 at 08:52:00AM +0200, Milan Broz wrote: > Please could you try if patch here helps and doesn't cause performance degradation? > <a href="http://www2.kernel.org/pub/linux/kernel/people/agk/patches/2.6/2.6.25/dm-crypt-add-cond_resched.patch" target="_blank">http://www2.kernel.org/pub/linux/kernel/people/agk/patches/2.6/2.6.25/dm-crypt-add-cond_resched.patch</a> </div>Will the result of testing a Debian 2.6.24-etchnhalf.1-amd64 kernel (very near a vanilla kernel) be of same value? Since the data on some other drives on this server is important so I dare not try 2.6.25-rc on it. Following is my test plan, comments are welcomed: Test command: # dd if=/dev/zero of=/dev/mapper/open_device bs=500M count=10 (this server has 2G memory) The command will be run for 3 times, and average speed of last two runs will be taken as result score. Dm-crypt LUKS Encryption scenarios: aes-cbc-essiv:sha256, keysize 128 aes-xts-plain, keysize 256 aes-xts-plain, keysize 512 I will compare the speed of all above 3 encryption scenarios, with and without the patch. -- Li, Yan </blockquote></div> -- Ritesh Raj Sarraf RESEARCHUT - <a href="http://www.researchut.com">http://www.researchut.com</a> "Necessity is the mother of invention."