From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f71.google.com (mail-pl0-f71.google.com [209.85.160.71]) by kanga.kvack.org (Postfix) with ESMTP id 19AEF6B04FE for ; Thu, 4 Jan 2018 18:13:12 -0500 (EST) Received: by mail-pl0-f71.google.com with SMTP id m39so1933017plg.19 for ; Thu, 04 Jan 2018 15:13:12 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org. [65.50.211.133]) by mx.google.com with ESMTPS id 69si2983817plc.769.2018.01.04.15.13.11 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 04 Jan 2018 15:13:11 -0800 (PST) Date: Thu, 4 Jan 2018 15:13:07 -0800 From: Matthew Wilcox Subject: Re: [PATCH 1/2] Move kfree_call_rcu() to slab_common.c Message-ID: <20180104231307.GA794@bombadil.infradead.org> References: <1514923898-2495-1-git-send-email-rao.shoaib@oracle.com> <20180102222341.GB20405@bombadil.infradead.org> <3be609d4-800e-a89e-f885-7e0f5d288862@oracle.com> <20180104013807.GA31392@tardis> <64ca3929-4044-9393-a6ca-70c0a2589a35@oracle.com> <20180104214658.GA20740@bombadil.infradead.org> <3e4ea0b9-686f-7e36-d80c-8577401517e2@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <3e4ea0b9-686f-7e36-d80c-8577401517e2@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: Rao Shoaib Cc: Boqun Feng , linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, brouer@redhat.com, linux-mm@kvack.org On Thu, Jan 04, 2018 at 02:18:50PM -0800, Rao Shoaib wrote: > > > > > +#define kfree_rcu(ptr, rcu_head_name) \ > > > > > + do { \ > > > > > + typeof(ptr) __ptr = ptr; \ > > > > > + unsigned long __off = offsetof(typeof(*(__ptr)), \ > > > > > + rcu_head_name); \ > > > > > + struct rcu_head *__rptr = (void *)__ptr + __off; \ > > > > > + __kfree_rcu(__rptr, __off); \ > > > > > + } while (0) > > > > why do you want to open code this? > > But why are you changing this macro at all? If it was to avoid the > > double-mention of "ptr", then you haven't done that. > I have -- I do not get the error because ptr is being assigned only one. If > you have a better way than let me know and I will be happy to make the > change. But look at the original: #define kfree_rcu(ptr, rcu_head) \ __kfree_rcu(&((ptr)->rcu_head), offsetof(typeof(*(ptr)), rcu_head)) ^^^ ^^^ versus your version: +#define kfree_rcu(ptr, rcu_head_name) \ + do { \ + typeof(ptr) __ptr = ptr; \ ^^^ ^^^ + unsigned long __off = offsetof(typeof(*(__ptr)), \ + rcu_head_name); \ + struct rcu_head *__rptr = (void *)__ptr + __off; \ + __kfree_rcu(__rptr, __off); \ + } while (0) I don't see the difference. -- 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