From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael David Crawford Subject: Re: How to minimize the compilation time of the XEN code Date: Tue, 01 Sep 2009 02:54:35 -0700 Message-ID: <4A9CEF5B.9060807@prgmr.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Keir Fraser wrote: > You can use the -j option to make to build in parallel, which speeds things > up quite a bit. In my tests on a quad core Xeon, I found that it was fastest to have more jobs than cores. That is, with my four cores, it was best to say "-j 8". The reason that works I think is that sometimes a job is blocked waiting for I/O. During that time a compute-bound job can run. If you only have as many jobs as cores, sometimes a core will be idle when its process is blocked. The best number of jobs will be highly dependent on your configuration though. It's worthwhile to test using the "time" command: time make -j 8 Mike -- Michael David Crawford mdc@prgmr.com prgmr.com - We Don't Assume You Are Stupid. Xen-Powered Virtual Private Servers: http://prgmr.com/xen