From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 16 Oct 2002 17:43:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 16 Oct 2002 17:42:00 -0400 Received: from pizda.ninka.net ([216.101.162.242]:23732 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Wed, 16 Oct 2002 17:41:11 -0400 Date: Wed, 16 Oct 2002 14:38:43 -0700 (PDT) Message-Id: <20021016.143843.99745166.davem@redhat.com> To: levon@movementarian.org Cc: weigand@immd1.informatik.uni-erlangen.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [8/7] oprofile - dcookies need to use u32 From: "David S. Miller" In-Reply-To: <20021016164057.GB85246@compsoc.man.ac.uk> References: <200210160156.DAA25005@faui11.informatik.uni-erlangen.de> <20021015.190019.41374479.davem@redhat.com> <20021016164057.GB85246@compsoc.man.ac.uk> X-FalunGong: Information control. X-Mailer: Mew version 2.1 on Emacs 21.1 / 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: John Levon Date: Wed, 16 Oct 2002 17:40:57 +0100 I'm not sure that's an option : o userspace needs to know the size of the cookie in the event buffer o userspace would like to use the cookie as a hash value to avoid repeated lookups Perhaps the best solution would be to use a separate u32 ID value, allocated linearly. I could just refuse to allocate new dcookies in theoretical case of overflow. The other possibility is a dcookiefs (cat /dev/oprofile/dcookie/34343234) but that's a lot of extra code/complexity ... I don't understand why using a bigger type is not an option. Why not just use u64? That would work too.