From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesse Barnes Date: Wed, 13 Oct 2004 19:28:21 +0000 Subject: Re: [RFC] Convert pgtable cache to slab Message-Id: <200410131428.21615.jbarnes@sgi.com> 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 Wednesday, October 13, 2004 2:07 pm, Luck, Tony wrote: > >With this patch I got a significant improvement in page fault time. > >Standard 2.4.x was about 700ns on average. Generic 2.6.9rc4 is 3-4 > >usec, whereas the slabified pgtcache drops us back down to 600-700 ns. > > What was the benchmark you were running when you measured these? > > >Tested on zx1 and sn2. > > How does this scale on big sn2 systems? I assume that the answers are > going to be just fine as the slab allocator per-cpu lists should be > just as nice as local quicklists, but it would be nice to see some > data. Yeah, it would be interesting, though page faults in general don't scale very well due to the way page_table_lock is used. Christoph had some patches for that, but I don't think he's had time to work on them lately. > Overall looks nice ... less code, and goes faster too, what more > could we ask for! > > Perhaps "zero_cache" isn't as descriptive a name as it might be (not > that I have any better suggestions :-( Maybe pgtable_zero_cache or something? Jesse