On Wed, 16 Mar 2005, Ingo Molnar wrote:
> > * Andrew Morton <[EMAIL PROTECTED]> wrote: > > > > ooh, I'd rather not. I spent an intense three days removing all the > > sleeping locks from ext3 (and three months debugging the result). > > Ended up gaining 1000% on 16-way. > > > > Putting them back in will really hurt the SMP performance. > > ah. Yeah. Sniff. > > if we gain 1000% on a 16-way then there's something really wrong about > semaphores (or scheduling) though. A semaphore is almost a spinlock, in > the uncontended case - and even under contention we really (should) just > spend the cycles that we'd spend spinning. There will be some > intermediate contention level where semaphores hurt, but 1000% sounds > truly excessive. > Could it possibly be that in the process of removing all the sleeping locks from ext3, that Andrew also removed a flaw in ext3 itself that is responsible for the 1000% improvement? -- Steve - 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/
