[PATCH] hvc_console polling mode timer backoff
will_schmidt at vnet.ibm.com
Fri Apr 13 04:43:30 EST 2007
On Thu, 2007-12-04 at 12:33 -0500, Linas Vepstas wrote:
> On Thu, Apr 12, 2007 at 11:14:36AM -0500, Will Schmidt wrote:
> > +/*
> > + * timeout will vary between the MIN and MAX values defined here. By default
> > + * and during console activity we will use a default MIN_TIMEOUT of 10. When
> > + * the console is idle, we increase the timeout value on each pass through
> > + * msleep until we reach the max. This may be noticeable as a brief (average
> > + * one second) delay on the console before the console responds to input when
> > + * there has been no input for some time.
> > + */
> > +#define MIN_TIMEOUT (10)
> > +#define MAX_TIMEOUT (2000)
> > + msleep_interruptible(timeout);
> These values are milliseconds (that's what the m in msleep stands for
> or at least it did last time I looked). This 10 is 1/100 of a second,
> which makes a responsive keyboard for even a very very fast typist.
> That's fine. But 2000 is two seconds, which is longer than the amount
> of time that I wait before I start panicking that something is broken.
Well, I usually give my systems at least ten seconds before I start to
I did ponder the max value to use. Though when I sit down at &random&
console in the lab, It often takes a moment for the terminal to warm up,
or for the screen to unblank. With that in mind, a couple seconds max
for the console does not seem unreasonable to me.
Will see if other folks have an opinion either way..
> I'd suggest that maybe 1000 or 750 or 500 is more apropriate.
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