From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751209AbWEMO43 (ORCPT ); Sat, 13 May 2006 10:56:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751207AbWEMO43 (ORCPT ); Sat, 13 May 2006 10:56:29 -0400 Received: from smtp106.mail.mud.yahoo.com ([209.191.85.216]:63331 "HELO smtp106.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1751195AbWEMO42 (ORCPT ); Sat, 13 May 2006 10:56:28 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=ojhoFyfEVReE3gm7r2epUttJnwQ5Qv/jnlgdO40UehHmem8qQssIVNPyRj56td7i3gWr59ErgwNhZjhwl0rFHF6E57FAD4RmX8/qSy0KU1IbJzZt0Jfz6CpWU97f7CaxRzTPMvyf8ieTMQ68j5tO46XoIImmy8kk+qsA65CWyVs= ; Message-ID: <4465F392.60102@yahoo.com.au> Date: Sun, 14 May 2006 00:56:18 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Steven Rostedt CC: Ingo Molnar , akpm@osdl.org, LKML Subject: Re: [PATCH] Silly bitmap size accounting fix References: <20060512091451.GA18145@elte.hu> <4465386B.9090804@yahoo.com.au> <4465EF80.6010106@yahoo.com.au> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Steven Rostedt wrote: > >>>+/* >>>+ * Calculate BITMAP_SIZE. >>>+ * The bitmask holds MAX_PRIO bits + 1 for the delimiter. >> >>+ * Calculation is to find the minimum number of longs that holds MAX_PRIO+1 bits: >>+ * size-in-chars = ceiling((MAX_PRIO+1) / CHAR_BITS) >>+ * size-in-longs = ceiling(size-in-chars / sizeof(long)) >> >> >>>+ */ >>> #define BITMAP_SIZE ((((MAX_PRIO+1+7)/8)+sizeof(long)-1)/sizeof(long)) >>> >> > > What do you think of the following comment, better? Cool, thanks. > > -- Steve > > Signed-off-by: Steven Rostedt > > Index: linux-2.6.17-rc3-mm1/kernel/sched.c > =================================================================== > --- linux-2.6.17-rc3-mm1.orig/kernel/sched.c 2006-05-12 04:02:32.000000000 -0400 > +++ linux-2.6.17-rc3-mm1/kernel/sched.c 2006-05-13 10:50:44.000000000 -0400 > @@ -192,6 +192,13 @@ static inline unsigned int task_timeslic > * These are the runqueue data structures: > */ > > +/* > + * Calculate BITMAP_SIZE. > + * The bitmask holds MAX_PRIO bits + 1 for the delimiter. > + * BITMAP_SIZE is the minimum number of longs that holds MAX_PRIO+1 bits: > + * size-in-bytes = ceiling((MAX_PRIO+1) / BITS_PER_BYTE) > + * size-in-longs = ceiling(size-in-bytes / sizeof(long)) > + */ > #define BITMAP_SIZE ((((MAX_PRIO+1+7)/8)+sizeof(long)-1)/sizeof(long)) > > typedef struct runqueue runqueue_t; > -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com