Messages in this thread | | | Date | Mon, 09 Dec 2002 22:55:45 -0800 | From | george anzinger <> | Subject | Re: [PATCH 1/3] High-res-timers part 1 (core) take 20 |
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Arjan van de Ven wrote: > > On Mon, Dec 09, 2002 at 04:27:56AM -0800, george anzinger wrote: > > > > > > that's why spinlocks are effectively nops on UP. > > > What you say is true of just about every spinlock user, and no > > > they shouldn't all do some IF_SMP() thing; the spinlock itself should be > > > (and is) zero on UP > > > > But with preemption, they really are not nops on UP... > > that doesn't justify fuglyfying the kernel code. If you can't live > with the overhead of preemption, disable preemption. Simple. > We DON'T want > spin_lock_nop_on_preempt() > ... > > spin_unlock_nop_on_preempt() > > really, I don't, and I can't see anyone else wanting that either
Well, I just thought it was an optimization. I will leave it the way it is.
-- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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