Messages in this thread | | | Date | Thu, 18 Mar 2004 19:00:59 +0100 | From | Andrea Arcangeli <> | Subject | Re: CONFIG_PREEMPT and server workloads |
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On Thu, Mar 18, 2004 at 12:48:50PM -0500, Robert Love wrote: > On Thu, 2004-03-18 at 09:51, Andrea Arcangeli wrote: > > > the counter is definitely not optimized away, see: > > This is because of work Dave Miller and Ingo did - irq count, softirq > count, and lock count (when PREEMPT=y) are unified into preempt_count. > > So it is intended. > > The unification makes things cleaner and simpler, using one value in > place of three and one interface and concept in place of many others. > It also gives us a single simple thing to check for an overall notion of > "atomicity", which is what makes debugging so nice.
You're right, I didn't notice the other counters disappeared. Those counter existed anyways w/o preempt too, so it would been superflous with preempt=y to do the accounting in two places. So this is zerocost with preempt=n and I was wrong claiming superflous preempt leftovers. - 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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