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From: Richard Miller <9fans@hamnavoe.com>
To: 9fans@9fans.net
Subject: Re: [9fans] usb slowness
Date: Tue,  6 Mar 2012 10:39:51 +0000	[thread overview]
Message-ID: <a8a4d75adaf927ca6d650b46859510c5@hamnavoe.com> (raw)
In-Reply-To: <2579b8.491be6b4.43V1.mx@tumtum.plumbweb.net>

> if i force polling, it's a little faster: 0.01u 0.45s 17.70r

That's interesting - it shouldn't make a difference unless there's something
wrong with the controller or the driver.  What did you do to force polling?

> holding a second, time wouldn't show interrupt-handling time, correct?

Yes, I think you're right - system cputime will only be incremented for
a running process.  But you can watch the last column of /dev/sysstat
(or use 'stats -I') to see the percentage of time spent in interrupt handlers.

> load remains fairly low during both, but system calls and context
> switches are high.

How about number of interrupts?  Erik's theory was that you were getting
too many of these.




      reply	other threads:[~2012-03-06 10:39 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-04  1:56 Tristan
2012-03-05 15:46 ` erik quanstrom
2012-03-05 16:05   ` Richard Miller
2012-03-05 16:14     ` erik quanstrom
2012-03-05 16:20       ` Richard Miller
2012-03-06 13:19   ` Tristan
2012-03-06 15:36     ` Tristan
2012-03-06 16:10       ` Richard Miller
2012-03-06 18:55       ` erik quanstrom
2012-03-06 22:22         ` Tristan
2012-03-07  5:50           ` Tristan
2012-03-07  5:53             ` Tristan
2012-03-07  9:31               ` Charles Forsyth
2012-03-10  3:13                 ` [9fans] donehead changed before ack Tristan
2012-03-10 12:33                   ` erik quanstrom
2012-03-10 15:14                     ` Tristan
2012-03-07 15:27           ` [9fans] usb slowness Richard Miller
2012-03-05 15:56 ` Richard Miller
2012-03-06  0:01   ` Tristan
2012-03-06 10:39     ` Richard Miller [this message]

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