Sebastian Huber sebastian.huber at
Wed Jul 19 12:41:49 UTC 2017

On 29/06/17 20:02, Kirspel, Kevin wrote:

> For those who run a RTEMS 4.12 single processor application with 
> LIBBSD, what percentage of time does your application spend in the 
> timer server task?  My NXP LPC3250 application spends about 13% of the 
> processor time processing the timer server.  Most of that time is 
> spent processing LIBBSD’s kernel callouts.  I am wondering if there is 
> an advantage to only call the FreeBSD’s callout_process() function 
> when we know a callout needs to be processed.  This would reduce the 
> number of RTEMS timer fires (which currently fire every tick).

I observed a similar problem a 96MHz LPC4088. The main issue is that 
callout_process() loads a lot of data (64-bit integers). So, on slow 
memory target, you have a performance issue with 1000 ticks per second.

Sebastian Huber, embedded brains GmbH

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