Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753962AbYCYHvH (ORCPT ); Tue, 25 Mar 2008 03:51:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751647AbYCYHu4 (ORCPT ); Tue, 25 Mar 2008 03:50:56 -0400 Received: from one.firstfloor.org ([213.235.205.2]:34574 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751296AbYCYHuz (ORCPT ); Tue, 25 Mar 2008 03:50:55 -0400 Date: Tue, 25 Mar 2008 08:54:03 +0100 From: Andi Kleen To: Ulrich Drepper Cc: Nicholas Miell , Andi Kleen , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH prototype] [0/8] Predictive bitmaps for ELF executables Message-ID: <20080325075403.GH2170@one.firstfloor.org> References: <20080320090005.GA25734@one.firstfloor.org> <20080321172644.GG2346@one.firstfloor.org> <20080322071755.GP2346@one.firstfloor.org> <1206170695.2438.39.camel@entropy> <20080322091001.GA7264@one.firstfloor.org> <1206335761.2438.63.camel@entropy> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1126 Lines: 24 On Mon, Mar 24, 2008 at 12:42:14PM -0700, Ulrich Drepper wrote: > On Sun, Mar 23, 2008 at 10:16 PM, Nicholas Miell wrote: > > The limit is filesystem dependent -- I think ext2/3s is something like > > 4k total for attribute names and values per inode. > > > > That's more than enough space for the largest executable on my system > > (emacs at 36788160 bytes) which would have a 1123 byte predictive bitmap > > (plus space for the name e.g. "system.predictive_bitmap"). The bitmap > > also could be compressed. > > 4k attribute means support for about 32768 pages. That's a total of > 134MB. I think this qualifies as sufficient. Also, I assume the > attribute limit is just a "because nobody needed more so far" limit > and could in theory be extended. There is still the additional seek. Large xattrs tend to be out of line from the inode. -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/