From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by fg-out-1718.google.com with SMTP id e12so453911fga.4 for ; Wed, 19 Mar 2008 17:16:49 -0700 (PDT) Date: Thu, 20 Mar 2008 01:15:20 +0100 From: Diego Calleja Subject: Re: [PATCH prototype] [0/8] Predictive bitmaps for ELF executables Message-Id: <20080320011520.60e151be.diegocg@gmail.com> In-Reply-To: <20080319020440.80379d50.akpm@linux-foundation.org> References: <20080318209.039112899@firstfloor.org> <20080318003620.d84efb95.akpm@linux-foundation.org> <20080318141828.GD11966@one.firstfloor.org> <20080318095715.27120788.akpm@linux-foundation.org> <20080318172045.GI11966@one.firstfloor.org> <20080318104437.966c10ec.akpm@linux-foundation.org> <20080319083228.GM11966@one.firstfloor.org> <20080319020440.80379d50.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Andi Kleen , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: El Wed, 19 Mar 2008 02:04:40 -0700, Andrew Morton escribio: > Assuming that all users have the same access pattern might be inefficient, > a little bit. There might be some advantage to making it per-user, dunno. In the Dark Side of operating systems, the prefetching system they use can log several access patterns for a single executable, because a single executable can have different behaviours even for the same user, depending on what parameters the executable is passed and what COM machinery it uses. For example, wmplayer.exe can play a dvd, rip a CD, listen to a music stream, etc...diferent usages, different access patterns. Linux probably faces the same problem (bash, cat...) A alternative design for a userspace solution that doesn't needs LD_PRELOAD is to use CONFIG_PROC_EVENTS to get notifications of what processes are started, which can be used to poll its /proc files or try to preload data (asynchronously, and a bit hacky maybe). But if a kernel patch is really needed to implement this properly, maybe it'd be worth to take a look at the prefetch project that the Ubuntu guys are apparently going to merge in the next ubuntu development release (8.10)... https://wiki.ubuntu.com/DesktopTeam/Specs/Prefetch There are even kernel patches: http://code.google.com/p/prefetch/source/browse/tags/soc2007-end/trunk/kernel-patches/2.6.22/submitted/0001-prefetch-core.diff http://code.google.com/p/prefetch/source/browse/tags/soc2007-end/trunk/kernel-patches/2.6.22/submitted/0002-prefetch-boot.diff -- 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