From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Date: Mon, 17 Nov 2008 12:30:00 -0800 (PST) > On Mon, 17 Nov 2008, David Miller wrote: > > > > It's on my workstation which is a much simpler 2 processor > > UltraSPARC-IIIi (1.5Ghz) system. > > Ok. It could easily be something like a cache footprint issue. And while I > don't know my sparc cpu's very well, I think the Ultrasparc-IIIi is super- > scalar but does no out-of-order and speculation, no? I does only very simple speculation, but you're description is accurate. > So I could easily see that the indirect branches in the scheduler > hurt much more, and might explain why the x86 profile looks so > different. Right. > One thing that non-NMI profiles also tend to show is "clumping", which in > turn tends to rather excessively pinpoint code sequences that release the > irq flag - just because those points show up in profiles, rather than > being a spread-out-mush. So it's possible that Ingo's profile did show the > scheduler more, but it was in the form of much more spread out "noise" > rather than the single spike you saw. Sure. -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
