From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Mallick, Asit K" Date: Wed, 23 Jul 2003 04:40:02 +0000 Subject: RE: [PATCH] don't use ld.bias Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org It does make sense to not use the ld.bias in the spinlock, it will make more cacheline bouncing in a larger SMP system. Thanks, Asit > -----Original Message----- > From: Jesse Barnes [mailto:jbarnes@sgi.com] > Sent: Tuesday, July 22, 2003 6:12 AM > To: Chen, Kenneth W > Cc: linux-ia64@vger.kernel.org; davidm@hpl.hp.com > Subject: Re: [PATCH] don't use ld.bias > > > On Mon, Jul 21, 2003 at 05:15:39PM -0700, Chen, Kenneth W wrote: > > > Patch to fix spin_lock to not use ld.bias since it causes > a bunch of > > bus > > > activity that hurts scalability when a lock is contended. > > > > It's dangerous to say something without knowing the whole > context, but I > > can't resist asking why not fix the contended lock area > instead? Sounds > > like you have some serious contention. > > Maybe I shouldn't have said 'contended'. This causes > problems even when > a lock is nearly uncontended. I agree that fixing lock > contention is a > good idea, but as I read this code, it'll only make the very best case > (totally uncontended) only a little better than if the > ld.bias were just > an ld and it makes the average and contended cases _much_ worse. > > I can get some data if you're not convinced by reading the code :) > > Thanks, > Jesse > - > To unsubscribe from this list: send the line "unsubscribe > linux-ia64" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >