From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from thermo.lanl.gov (thermo.lanl.gov [128.165.59.202]) by mailwasher-b.lanl.gov (8.12.11/8.12.11/(ccn-5)) with SMTP id jA4GEOHB001149 for ; Fri, 4 Nov 2005 09:14:24 -0700 Subject: Re: [Lhms-devel] [PATCH 0/7] Fragmentation Avoidance V19 In-Reply-To: Message-Id: <20051104161420.9CFA8184631@thermo.lanl.gov> Date: Fri, 4 Nov 2005 09:14:20 -0700 (MST) From: andy@thermo.lanl.gov (Andy Nelson) Sender: owner-linux-mm@kvack.org Return-Path: To: andy@thermo.lanl.gov, torvalds@osdl.org Cc: akpm@osdl.org, arjan@infradead.org, arjanv@infradead.org, haveblue@us.ibm.com, kravetz@us.ibm.com, lhms-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mbligh@mbligh.org, mel@csn.ul.ie, mingo@elte.hu, nickpiggin@yahoo.com.au List-ID: Linus: >> If your and other kernel developer's (<<0.01% of the universe) kernel >> builds slow down by 5% and my and other people's simulations (perhaps >> 0.01% of the universe) speed up by a factor up to 3 or 4, who wins? > >First off, you won't speed up by a factor of three or four. Not even >_close_. My measurements of factors of 3-4 on more than one hw arch don't mean anything then? BTW: Ingo Molnar has a response that did find my comp.arch posts. As I indicated to him, I've done a lot of code tuning to get better performance even in the presence of tlb issues. This factor is what is left. Starting from an untuned code, the factor can be up to an order of magnitude larger. As in 30-60. Yes, I've measured that too, though these detailed measurments were only on mips/origins. It is true that I have never had the opportunity to test these issues on x86 and its relatives. Perhaps it would be better there. The relative insensitivity of the results I have already to hw arch, indicate otherwise though. Re maintainability: Fine. I like maintainable code too. Coding standards are great. Language standards are even better. These are motherhood statements. Your simple rejections ("NO, HELL NO!!") even of any attempts to make these sorts of improvements seems to make that issue pretty moot anyway. Andy -- 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/ . Don't email: email@kvack.org