Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [PATCH] x86_64 add missing enter_idle() calls | Date | Mon, 16 Oct 2006 16:36:52 +0200 |
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> With the original code, the number of callbacks you see for IDLE_START and > IDLE_STOP is not too obvious. > > On an idle system Opteron 250 with HZ=250, one would expect to see for a 10s duration: > - for CPU0 : IDLE_START = IDLE_STOP = about 5000 calls > - for other CPUs: IDLE_START = IDLE_STOP = about 2500 calls
Yes.
> With the original code, you get the following number of calls: > > CPU0.IDLE_START = 44 (enter_idle) > CPU0.IDLE_STOP = 5206 (exit_idle) > > CPU1.IDLE_START = 27 (enter_idle) > CPU1.IDLE_STOP = 2528 (exit_idle) > > Now, of course, you may get "batched" interrupts where you do not return to idle > before you process the next interrupt. But the difference seems quite high here.
Shouldn't happen for timer interrupts. > > Do you have an explanation for this?
Hmm, the last time I fixed this when you complained (post .18) i added a counter for entry/exit and verified that it was balanced. I haven't rechecked since then. I don't know why your numbers are off. You're using the latest git tree, right?
-Andi
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