Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754134AbcJKRWe (ORCPT ); Tue, 11 Oct 2016 13:22:34 -0400 Received: from mail-lf0-f68.google.com ([209.85.215.68]:36031 "EHLO mail-lf0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753425AbcJKRWd (ORCPT ); Tue, 11 Oct 2016 13:22:33 -0400 Date: Tue, 11 Oct 2016 19:22:29 +0200 From: Michal Hocko To: zijun_hu Cc: tj@kernel.org, akpm@linux-foundation.org, zijun_hu@htc.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cl@linux.com Subject: Re: [RFC PATCH 1/1] mm/percpu.c: fix memory leakage issue when allocate a odd alignment area Message-ID: <20161011172228.GA30403@dhcp22.suse.cz> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 643 Lines: 16 On Tue 11-10-16 21:24:50, zijun_hu wrote: > From: zijun_hu > > the LSB of a chunk->map element is used for free/in-use flag of a area > and the other bits for offset, the sufficient and necessary condition of > this usage is that both size and alignment of a area must be even numbers > however, pcpu_alloc() doesn't force its @align parameter a even number > explicitly, so a odd @align maybe causes a series of errors, see below > example for concrete descriptions. Is or was there any user who would use a different than even (or power of 2) alighment? If not is this really worth handling? -- Michal Hocko SUSE Labs