From: Michael David Crawford <mdc@prgmr.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: Re: How to minimize the compilation time of the XEN code
Date: Tue, 01 Sep 2009 02:54:35 -0700 [thread overview]
Message-ID: <4A9CEF5B.9060807@prgmr.com> (raw)
In-Reply-To: <C6C2AACF.13A3A%keir.fraser@eu.citrix.com>
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
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prev parent reply other threads:[~2009-09-01 9:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-01 8:11 How to minimize the compilation time of the XEN code Wen.Tian
2009-09-01 9:41 ` Keir Fraser
2009-09-01 9:54 ` Michael David Crawford [this message]
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