Re: [PATCH 08/57] microblaze_v7: Interrupt handling, timer support,selfmod code

From: Thomas Gleixner
Date: Fri Mar 20 2009 - 06:50:21 EST


On Fri, 20 Mar 2009, Michal Simek wrote:
> Why is my .resolution: 10000000 nsecs? It seems to me weird.

Well. The resulution there is the granularity which the kernel uses to
expire application timers. Once the kernel switches to high resolution
mode it sets the granularity to 1ns.

To get high resolution mode you need two things:

1) a suitable clocksource - which needs to have the
CLOCK_SOURCE_IS_CONTINUOUS flag set

2) a clock event device which has CLOCK_EVT_FEAT_PERIODIC flag set.

3) CONFIG_HIGH_RES_TIMERS=y

Thanks,

tglx
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