Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 9 Nov 2001 02:25:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 9 Nov 2001 02:25:23 -0500 Received: from pizda.ninka.net ([216.101.162.242]:21890 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Fri, 9 Nov 2001 02:24:34 -0500 Date: Thu, 08 Nov 2001 23:24:25 -0800 (PST) Message-Id: <20011108.232425.21928928.davem@redhat.com> To: akpm@zip.com.au Cc: ak@suse.de, anton@samba.org, mingo@elte.hu, linux-kernel@vger.kernel.org Subject: Re: speed difference between using hard-linked and modular drives? From: "David S. Miller" In-Reply-To: <3BEB82B8.541558CA@zip.com.au> In-Reply-To: <3BEB7DA6.BC8793B1@zip.com.au> <20011108.231717.85686073.davem@redhat.com> <3BEB82B8.541558CA@zip.com.au> X-Mailer: Mew version 2.0 on Emacs 21.0 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Andrew Morton Date: Thu, 08 Nov 2001 23:16:08 -0800 Well on my setup, there are more hash buckets than there are pages in the system. So - basically empty. If memory serves me, never more than two pages in a bucket. Ok, this is what I expected. The function is tuned for having N_HASH_CHAINS being roughly equal to N_PAGES. If you want to experiment with smaller hash tables, there are some hacks in the FreeBSD sources that choose a different "salt" per inode. You xor the salt into the hash for each page on that inode. Something like this... Franks a lot, David S. Miller davem@redhat.com - 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/