Re: [GIT PULL] omap changes for v2.6.39 merge window

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, 2011-04-04 at 01:59 +0100, Arnd Bergmann wrote:
> On Sunday 03 April 2011, Russell King - ARM Linux wrote:
> > Then there's those which change the cs->read function pointer at runtime,
...
> > and those which share that pointer with their sched_clock() implementation.
> 
> Abstracting sched_clock() to be run-time selected is something that
> needs to be taken care of. Maybe we could have a generic sched_clock
> implementation that is written on top of clocksource instead of jiffies,
> and always select that on architectures that have a decent clocksource.

On Cortex-A15 with the virtualisation extensions and architected timers
the clocksource is implemented using a physical counter (as we want
wall-clock timing). But for sched_clock() we may want to use a virtual
counter (which is basically an offset from the physical one, set by the
hypervisor during guest OS switching). Marc already posted some patches
for this.

-- 
Catalin


--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Arm (vger)]     [ARM Kernel]     [ARM MSM]     [Linux Tegra]     [Linux WPAN Networking]     [Linux Wireless Networking]     [Maemo Users]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Trails]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux