From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id E3D166B003D for ; Fri, 8 Jan 2010 10:52:17 -0500 (EST) Date: Fri, 8 Jan 2010 09:51:49 -0600 (CST) From: Christoph Lameter Subject: Re: [RFC][PATCH 6/8] mm: handle_speculative_fault() In-Reply-To: <20100107204940.253ed753@infradead.org> Message-ID: References: <20100104182429.833180340@chello.nl> <20100104182813.753545361@chello.nl> <20100105054536.44bf8002@infradead.org> <20100105192243.1d6b2213@infradead.org> <20100107204940.253ed753@infradead.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Arjan van de Ven Cc: Linus Torvalds , Peter Zijlstra , "Paul E. McKenney" , Peter Zijlstra , KAMEZAWA Hiroyuki , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "minchan.kim@gmail.com" , "hugh.dickins" , Nick Piggin , Ingo Molnar List-ID: On Thu, 7 Jan 2010, Arjan van de Ven wrote: > if an app has to change because our kernel sucks (for no good reason), > "change the app" really is the lame type of answer. We are changing apps all of the time here to reduce the number of system calls. Any system call usually requires context switching, scheduling activities etc. Evil effects if you want the processor for computation and are sensitive to cpu caching effects. It is good to reduce the number of system calls as much as possible. System calls are at best placed to affect the largest memory possible in a given context and be avoided in loops. -- 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