lkml.org 
[lkml]   [2012]   [Mar]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] regulator: notify sysfs when voltage is set
On Thu, Mar 15, 2012 at 12:46:31PM +0000, Mark Brown wrote:
> On Thu, Mar 15, 2012 at 09:04:33PM +0900, Simon Horman wrote:
>
> > This allows libudev to be used to monitor voltage changes and thus allows
> > user-space code to avoid polling the sysfs entry for changes.
>
> I notice that we don't generate similar events for cpufreq... what are
> the performance implications from firing off udev (which isn't free)
> every time we scale the CPU frequency? It feels like this might be
> disruptive, especially with a governor like ondemand which responds to
> system load.

Hi Mark,

that is a good point and to be honest not one that I had considered. For
the use-case that I have in mind, which is basically to log voltage changes
over time, it may be acceptable to rate-limit notifications somehow. But at
that point I may be better off just polling.

Out of interest, how often can ondemand potentially change the voltage?


\
 
 \ /
  Last update: 2012-03-15 15:29    [W:0.043 / U:10.396 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site