Corey,

I don't understand this patch.
You say:
"This patch fixes a problem with accessing the array of cpu-specific PMU
counters, where there was a race condition that could occur where we
acquire the cpu number, and then have the cpu switch out from underneath
us.  Using get_cpu()/put_cpu() fixes this problem because get_cpu()
disables preemption until put_cpu() is called again."

What do you mean by "switch from underneath". AFAIK, pmd_sread() is called
with interrupts masked. I thought, this was enough to prevent any preemption?



On Mon, Jul 14, 2008 at 11:50 PM, Corey Ashford <[EMAIL PROTECTED]> wrote:
> This fixes an issue on POWER4 and POWER6 where PMU exceptions need to be
> disabled when the context is in masked mode.
>
> --
> Corey Ashford
> Software Engineer
> IBM Linux Technology Center, Linux Toolchain
> Beaverton, OR
> 503-578-3507
> [EMAIL PROTECTED]
>

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