[PATCH] powerpc/time: avoid programming DEC at the start of the timer interrupt

[Michael Ellerman]

On Sat, 10 Sep 2022 00:24:57 +1000, Nicholas Piggin wrote:
> Setting DEC to maximum at the start of the timer interrupt is not
> necessary and can be avoided for performance when MSR[EE] is not
> enabled during the handler as explained in commit 0faf20a1ad16
> ("powerpc/64s/interrupt: Don't enable MSR[EE] in irq handlers unless
> perf is in use"), where this change was first attempted.
> 
> The idea is that the timer interrupt runs with MSR[EE]=0, and at the end
> of the interrupt DEC is programmed to the next timer interval, so there
> is no need to clear the decrementer exception before then.
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc/time: avoid programming DEC at the start of the timer interrupt
      https://git.kernel.org/powerpc/c/c84550203b3173511e8cdbe94bc2e33175ba1d72

cheers