svn commit: r278479 - in head: etc sys/kern

[Slawa Olhovchenkov]

On Tue, Feb 10, 2015 at 06:30:27PM +0000, Rui Paulo wrote:

> On Feb 10, 2015, at 07:37 AM, John Baldwin <jhb at freebsd.org> wrote:
> That wasn't really my question. My question was if we want distinct streams 
> or if we want want unified stream. Having a unified stream might very well 
> make sense (and if so we could rename devd to make that more obvious).
> 
> I'm fine with renaming devd to eventd or something else, but Ian was
> saying that he's worried about the number of notifications that devd
> has to process.  I'm not sure that's a real problem at this point,
> though.  On freefall, devd used 0.07 seconds of CPU time and has
> been running for a 1 day and a half.  On my BeagleBone, devd used
> 0.61 seconds of CPU time and it has been up for 5 days and a half.  
> On my VM that has been up for 5 days and a half, it used 4 seconds
> of CPU time.  Renaming sounds like a good idea and it looks like we
> could leave the optimisations to a later time.

For common case (I am not talk about current devd implementation -- I
am don't have any inforamtion/metrics/etc) routing and processing
events may be sensitive to delay and ordering: may be exist
requirement 'delay not more then 700ns', may be exist requirement
'next event process only after complete process previos event'. And
some event handling may be very CPU/disk/etc consumption. Need to good
think over and design API and architecure.