From: Gene Heskett <gene.heskett@gmail.com>
To: Mike Galbraith <efault@gmx.de>,
LKML <linux-kernel@vger.kernel.org>,
emc-users@lists.sourceforge.net
Subject: Re: isolcpus question
Date: Tue, 31 Jan 2012 01:31:19 -0500 [thread overview]
Message-ID: <201201310131.20239.gene.heskett@gmail.com> (raw)
In-Reply-To: <1327985246.6667.8.camel@marge.simson.net>
On Monday, January 30, 2012, Mike Galbraith wrote:
>On Mon, 2012-01-30 at 22:13 -0500, Gene Heskett wrote:
>> Which is, is there a isolcpus troubleshooting tool?
>>
>> I have an app that is supposed to use the 2nd cpu on a 2 core atom
>> system all by itself, and its insisting on using cpu0 when the boot
>> command line has "isolcpus=1" appended to it, and apparently I am the
>> only one with the problem, its working for about 200-500 others
>> running the same software.
>
>isolcpus=1 isolates CPU1 so no task will automatically end up using it,
>but it's up to your task (or you) to move to the isolated CPU. Pin your
>task to CPU1 with taskset, and all should work fine.
>
> -Mike
Cross-posted back to the emc-users list, others might find it useful also.
Mike, you're a genius. The man page for taskset is a bit obtuse but the
first stab at a '/usr/bin/lcnc' script:
-------------
#!/bin/bash
taskset 0x00000002 emc -l
exit 0
-------------
Seems to launch this application and I believe its now working better than
ever before. Now I need to do some experimenting to see just how fast I
can make linuxcnc's base_thread run without the rest of the box getting
laggy. The faster I can make that thread run, the faster and smoother my
steppers driving my milling machine will run. I have already cut it down
to 30 u-secs from 65 u-secs and it is still only using about 26% of the
target cpu1. Amazing IMO.
Thank you very much Mike.
Cheers, Gene
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: <http://coyoteden.dyndns-free.com:85/gene>
When a lion meets another with a louder roar,
the first lion thinks the last a bore.
-- G.B. Shaw
prev parent reply other threads:[~2012-01-31 6:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-31 3:13 isolcpus question Gene Heskett
2012-01-31 4:47 ` Mike Galbraith
2012-01-31 6:31 ` Gene Heskett [this message]
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