From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 1 Jan 2003 21:25:04 -0800 From: William Lee Irwin III Subject: Re: 2.5.53-mm2 Message-ID: <20030102052504.GQ9704@holomorphy.com> References: <3E0E4744.8EE126ED@digeo.com> <20030102045327.GC7644@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030102045327.GC7644@holomorphy.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton , lkml , linux-mm@kvack.org List-ID: On Sat, Dec 28, 2002 at 04:52:20PM -0800, Andrew Morton wrote: >> wli-11_pgd_ctor.patch On Wed, Jan 01, 2003 at 08:53:27PM -0800, William Lee Irwin III wrote: > A moment's reflection on the subject suggests to me it's worthwhile to > generalize pgd_ctor support so it works (without #ifdefs!) on both PAE > and non-PAE. This tiny tweak is actually more noticeably beneficial > on non-PAE systems but only really because pgd_alloc() is more visible; > the most likely reason it's less visible on PAE is "other overhead". > It looks particularly nice since it removes more code than it adds. > Touch tested on NUMA-Q (PAE). OFTC #kn testers testing the non-PAE case. For those needing more interpretation, this is essentially a reinstatement of the 2.4.x-style pgd/pmd cache optimization in a leak-free and accounted (in /proc/slabinfo) manner. The point of the optimizations is that these initializations are large cache hits to take in a single shot, and in the PAE case, amount to a full L1 cache flush as they traverse almost an entire 16K. No rigorous benchmarking has been done yet. Bill -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/