From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90F8BC43381 for ; Wed, 20 Mar 2019 11:20:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5EEC02184E for ; Wed, 20 Mar 2019 11:20:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="P5Xhif6s" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727741AbfCTLUA (ORCPT ); Wed, 20 Mar 2019 07:20:00 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:44156 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727154AbfCTLUA (ORCPT ); Wed, 20 Mar 2019 07:20:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=X0UZ2Ky/zStGHPaiYjOhz7nuC7+B3z5ZswtS2vYbX0k=; b=P5Xhif6soKuu27UyLw0TJwt/C g7xrtrWG+7HryAGydpaDjOzzLE9hFy3fvrjNfU6qMKF/chFBOkOCGxxmntD1+x0rR+bV4YU33Lh4Z SK4dVmHgpGdCjSvZrwf1xQ1ib9/Du59c0XiSCwlT/FRVBuPZYYkHS8dbNVCpPzrtnYzsoJQJKnIgf OB6sdGR8ndX/HMvYrV6Qtp9sRvO1cc++XFEwXrDujZN248gpAulDa0RZsHpRTWocZlWQsEGmCS0IY ReAOcRWeLdr0STaS8VT7lut7bUqEbKmpgPDfEPdX8qfcGO1SiABMYc/usMdt30poz+7CBpRiWBBHu oFlP3BEqQ==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1h6ZGJ-0005lm-Qz; Wed, 20 Mar 2019 11:19:59 +0000 Date: Wed, 20 Mar 2019 04:19:59 -0700 From: Matthew Wilcox To: Baoquan He Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, pasha.tatashin@oracle.com, mhocko@suse.com, rppt@linux.vnet.ibm.com, richard.weiyang@gmail.com, linux-mm@kvack.org Subject: Re: [PATCH 1/3] mm/sparse: Clean up the obsolete code comment Message-ID: <20190320111959.GV19508@bombadil.infradead.org> References: <20190320073540.12866-1-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190320073540.12866-1-bhe@redhat.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 20, 2019 at 03:35:38PM +0800, Baoquan He wrote: > /* > - * returns the number of sections whose mem_maps were properly > - * set. If this is <=0, then that means that the passed-in > - * map was not consumed and must be freed. > + * sparse_add_one_section - add a memory section > + * @nid: The node to add section on > + * @start_pfn: start pfn of the memory range > + * @altmap: device page map > + * > + * Return 0 on success and an appropriate error code otherwise. > */ I think it's worth documenting what those error codes are. Seems to be just -ENOMEM and -EEXIST, but it'd be nice for users to know what they can expect under which circumstances. Also, -EEXIST is a bad errno to return here: $ errno EEXIST EEXIST 17 File exists What file? I think we should be using -EBUSY instead in case this errno makes it back to userspace: $ errno EBUSY EBUSY 16 Device or resource busy