From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763827AbYD0Ul4 (ORCPT ); Sun, 27 Apr 2008 16:41:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751364AbYD0Uls (ORCPT ); Sun, 27 Apr 2008 16:41:48 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:50646 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751033AbYD0Ulr (ORCPT ); Sun, 27 Apr 2008 16:41:47 -0400 Date: Sun, 27 Apr 2008 22:41:29 +0200 From: Ingo Molnar To: David Miller Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, viro@ZenIV.linux.org.uk, Alexander van Heukelum Subject: Re: find_new_bit bloat from x86 tree... Message-ID: <20080427204129.GB25300@elte.hu> References: <20080426.220726.13692428.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080426.220726.13692428.davem@davemloft.net> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * David Miller wrote: > Ingo, what the heck is this? > > commit 64970b68d2b3ed32b964b0b30b1b98518fde388e > Author: Alexander van Heukelum (Alexander Cc:-ed.) > Date: Tue Mar 11 16:17:19 2008 +0100 > > x86, generic: optimize find_next_(zero_)bit for small constant-size bitmaps > > Thanks for bloating up the inline expansion of this thing on every > architecture that doesn't do __ffs() in a simple sequence of a few > instructions like x86 does. ok, that's bad. How much is the before/after vmlinux btw, i guess you measured it? We could either make it per arch selectable, or we could just uninline it all. It shouldnt be a big deal on x86 and it should help on RISC platforms. Ingo