From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Schwab Subject: Re: [KJ] [PATCH] is_power_of_2 in ia64mm References: <1171627435.6127.0.camel@wriver-t81fb058.linuxcoe> <45D5C789.1090607@student.ltu.se> 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: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org Return-Path: 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 List-ID: 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, Maxfeldstrasse 5, 90409 Nurnberg, Germany PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org