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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 E50CCC43441 for ; Tue, 27 Nov 2018 15:27:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB9FE20817 for ; Tue, 27 Nov 2018 15:27:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB9FE20817 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mansr.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729649AbeK1C0E convert rfc822-to-8bit (ORCPT ); Tue, 27 Nov 2018 21:26:04 -0500 Received: from unicorn.mansr.com ([81.2.72.234]:48840 "EHLO unicorn.mansr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729309AbeK1C0E (ORCPT ); Tue, 27 Nov 2018 21:26:04 -0500 X-Greylist: delayed 444 seconds by postgrey-1.27 at vger.kernel.org; Tue, 27 Nov 2018 21:26:03 EST Received: by unicorn.mansr.com (Postfix, from userid 51770) id E2002149B5; Tue, 27 Nov 2018 15:20:24 +0000 (GMT) From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Matthew Wilcox Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: fix insert_pfn() return value References: <20181127144351.9137-1-mans@mansr.com> <20181127150852.GA10377@bombadil.infradead.org> Date: Tue, 27 Nov 2018 15:20:24 +0000 In-Reply-To: <20181127150852.GA10377@bombadil.infradead.org> (Matthew Wilcox's message of "Tue, 27 Nov 2018 07:08:52 -0800") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Matthew Wilcox writes: > On Tue, Nov 27, 2018 at 02:43:51PM +0000, Mans Rullgard wrote: >> Commit 9b5a8e00d479 ("mm: convert insert_pfn() to vm_fault_t") accidentally >> made insert_pfn() always return an error. Fix this. > > Umm. VM_FAULT_NOPAGE is not an error. It's saying "I inserted the PFN, > there's no struct page for the core VM to do anything with". Which is > the correct response from a device driver which has called insert_pfn(). > > Could you explain a bit more what led you to think there's a problem here? Apparently some (not in mainline) driver code had been hastily converted to the vm_fault_t codes, and that is where the error is. Sorry for the noise. Please disregard this. (The quickest way to get the correct answer is still to send a bad patch.) > Also, rather rude of you not to cc the patch author when you claim to > be fixing a bug in their patch. Sorry about that. Blame the get-maintainers script. -- Måns Rullgård