From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 25 Mar 2008 08:54:03 +0100 From: Andi Kleen 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: Sender: owner-linux-mm@kvack.org Return-Path: To: Ulrich Drepper Cc: Nicholas Miell , Andi Kleen , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: 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, 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