On 27.04.2012, at 18:37, Scott Wood <scottwood@xxxxxxxxxxxxx> wrote: > On 04/27/2012 06:23 AM, Alexander Graf wrote: >> >> On 27.04.2012, at 07:48, Paul Mackerras wrote: >> >>> Have you measured a performance improvement with this patch? If so >>> how big was it? >> >> Yeah, I tried things on 970 in an mfsprg/mtsprg busy loop. I measured 3 different variants: >> >> C irq handling: 1004944 exits/sec >> asm irq handling: 1001774 exits/sec >> asm + hsrr patch: 994719 exits/sec >> >> So as you can see, that code change does have quite an impact. But >> maybe the added complexity isn't worth it? Either way, we should try >> and find a solution that works the same way for booke and book3s - I >> don't want such an integral part to differ all that much. > > Is it really added complexity, considering what you can remove from the > asm? I went with C handling on bookehv because it seemed simpler (the > original internal version had asm handling). Well, the addition in complexity is that you have to start thinking about more things than before :). I'm not sure really which way is better in the long run. Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
