From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932326AbdJYSLN (ORCPT ); Wed, 25 Oct 2017 14:11:13 -0400 Received: from ale.deltatee.com ([207.54.116.67]:38050 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932124AbdJYSLM (ORCPT ); Wed, 25 Oct 2017 14:11:12 -0400 To: Daniel Mentz , sbates@raithlin.com Cc: corbet@lwn.net, Mathieu Desnoyers , Andrew Morton , Will Deacon , lkml References: <1508945574-25984-1-git-send-email-sbates@raithlin.com> From: Logan Gunthorpe Message-ID: Date: Wed, 25 Oct 2017 12:11:07 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, will.deacon@arm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, corbet@lwn.net, sbates@raithlin.com, danielmentz@google.com X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH] genalloc: Make the avail variable an atomic64_t X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25/10/17 11:55 AM, Daniel Mentz wrote: > avail is defined as size_t (32 bit). Aren't you going to overflow that variable? I think the point is to get support for 64-bit systems (ie. ARM64 and x64. We're working with large PCI BARs and need some way to allocate memory from them. You aren't likely to ever get >4GB chunks on 32-bit systems but you certainly can on 64-bit systems. Logan