Messages in this thread | | | Date | Fri, 22 Jun 2007 16:23:05 +1000 | Subject | Re: [RFC] clocksouce implementation for powerpc | From | (Tony Breeds) |
| |
On Wed, Jun 20, 2007 at 07:57:19AM -0700, Daniel Walker wrote:
Hi Daniel.
> As I said in our private thread, I do think you should be using > update_vsyscall() .. update_vsyscall() is just called when the time is > set, usually that happens in the timer interrupt and sometimes that > happens in settimeofday() ..
Well I've taken another look at the code and I think I can probably restructure my code to use update_vsyscall(). I thought I needed a hook that was called /only/ from settimeofday() (which as you say doesn't match update_vsyscall()'s usage).
I'll try again and see what problems I hit.
> At least some of your code is duplications over what is already being > worked on inside the powerpc community.. For instance, I know there is > already a timebase clocksource, > > http://people.redhat.com/~mingo/realtime-preempt/patch-2.6.21.5-rt17
Thanks. The one in -rt doesn't seem to support the VDSO. however I see that there is duplication of effort there.
> Hmm .. This doesn't look like it's taking into account that the time has > changed .. Your time has effectively incremented by one jiffie .. The > vdso_data doesn't appear to be updated ..
Unless I miss your meaning, the vdso is updated in timer_recalc_offset()/update_gtod() when needed.
Yours Tony
linux.conf.au http://linux.conf.au/ || http://lca2008.linux.org.au/ Jan 28 - Feb 02 2008 The Australian Linux Technical Conference!
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |