Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1945902AbXBPPOI (ORCPT ); Fri, 16 Feb 2007 10:14:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1945904AbXBPPOI (ORCPT ); Fri, 16 Feb 2007 10:14:08 -0500 Received: from cantor2.suse.de ([195.135.220.15]:54543 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1945902AbXBPPOG (ORCPT ); Fri, 16 Feb 2007 10:14:06 -0500 From: Andreas Schwab To: Richard Knutsson Cc: Vignesh Babu BM , Kernel Janitors List , linux-mm@kvack.org, tony.luck@intel.com, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [KJ] [PATCH] is_power_of_2 in ia64mm References: <1171627435.6127.0.camel@wriver-t81fb058.linuxcoe> <45D5C789.1090607@student.ltu.se> X-Yow: Now I understand the meaning of ``THE MOD SQUAD''! Date: Fri, 16 Feb 2007 16:13:55 +0100 In-Reply-To: <45D5C789.1090607@student.ltu.se> (Richard Knutsson's message of "Fri, 16 Feb 2007 16:02:33 +0100") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/22.0.91 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1170 Lines: 31 Richard Knutsson writes: > Vignesh Babu BM wrote: >> @@ -175,7 +176,7 @@ static int __init hugetlb_setup_sz(char *str) >> tr_pages = 0x15557000UL; >> size = memparse(str, &str); >> - if (*str || (size & (size-1)) || !(tr_pages & size) || >> + if (*str || !is_power_of_2(size) || !(tr_pages & size) || >> size <= PAGE_SIZE || >> size >= (1UL << PAGE_SHIFT << MAX_ORDER)) { >> printk(KERN_WARNING "Invalid huge page size specified\n"); >> >> > As we talked about before; is this really correct? !is_power_of_2(0) == > true while (0 & (0-1)) == 0. size == 0 is also covered by the next two conditions, so the overall value does not change. Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux Products GmbH, Maxfeldstra?e 5, 90409 N?rnberg, Germany PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." - 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/