From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jack Steiner Date: Wed, 26 Nov 2003 19:02:30 +0000 Subject: Re: [PATCH] - kernel profiler & spinlock_contention 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 On Wed, Nov 26, 2003 at 09:31:02AM -0800, David Mosberger wrote: > >>>>> On Wed, 26 Nov 2003 09:23:10 -0600, Jack Steiner said: > > Jack> Profiling is more useful if addresses in spinlock_contention > Jack> were attributed to the caller of spinlock_contention. > > Execuse the language, but I'm reading: > > my tools suck so let's make the kernel suck! I dont quite agree. The way it work right now, profiling on large systems is useless. The single hotest spot in the kernel is spinlock_contention & there is no clue why. The patch makes the kernel work the way it did before spinning for locks was moved out-of-line. I think that is a big improvement. However, if your new tools allows me to determine the caller of spinlock_contention (I'm guessing that it does), that is even better!! If a prerelease version of the tools is available, I'll be happy to try it on our system > > Let's defer this discussion until next week, when I had a chance to > release my profiling tool. I think you'll then agree that it's much > better to leave the code as is. In fact, we should also have an > out-of-line contention handler for the read/write locks. Agree! > > --david -- Thanks Jack Steiner (steiner@sgi.com) 651-683-5302 Principal Engineer SGI - Silicon Graphics, Inc.