On Wed, 13 Jul 2005, Lee Revell wrote: > Did anyone else find this strange: > > "The RTC is used in periodic mode to provide the system profiling > interrupt on uni-processor systems and the clock interrupt on > multi-processor systems." > > We just take NR_CPUS * HZ timer interrupts per second, what's the > advantage of using the RTC? It tends to work in the APIC mode all the time (with all systems), unlike the PIT which has "interesting" routing problems with its IRQ0, which you've probably already noticed. Have a look at all the hassle in check_timer() if you want to double-check it. Of course using APIC internal timers is generally the best idea on SMP, but they may have had reasons to avoid them (it's not an ISA interrupt, so it could have been simply out of question in the initial design). Maciej - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
- References:
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: Bill Davidsen <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: David Lang <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: Vojtech Pavlik <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: Linus Torvalds <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: Lee Revell <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: Dmitry Torokhov <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: Lee Revell <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: Andrew Morton <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: Chris Wedgwood <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: dean gaudet <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: Chris Wedgwood <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: dean gaudet <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- From: Lee Revell <[email protected]>
- Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- Prev by Date: Re: [PATCH] Fuse chardevice number
- Next by Date: Re: 2.6.13-rc2-mm2
- Previous by thread: Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- Next by thread: Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt
- Index(es):