[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 2/4] CPUIDLE: Avoid remnant LAPIC timer intr while force hpetbroadcast
On 10/9/08 15:25, "Wei, Gang" <gang.wei@xxxxxxxxx> wrote: >> It's not clear to me the disable/enable_LAPIC_timer() work is worthwhile for >> the few timer interrupts it is likely to avoid. The other bit of the patch >> is a good bugfix though. I've taken just the latter part. > > Thanks for accept most of these patches. As to disable/enable_LAPIC_timer(), I > add them because some platforms require the LAPIC timer intr being disabled > before entering C3, otherwise there may be some unexpected things. As a > reference, Linux kernel always do so. Can you point out where Linux does so? It's not obvious to me. Also, in your patch, you unmask LVTT after reprogramming the LAPIC counter. Isn't there a race where the LAPIC timer generates an interrupt event before you unmask the LVTT and hence you lose the interrupt (since I assume the LAPIC interrupt is basically an internal one-shot signal which does not get latched in any way)? So you'd probably need to reprogram_timer(0), then enable the timer, then reprogram_timer(<actual value>). -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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