From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by kanga.kvack.org (Postfix) with ESMTP id 3D6036B48A6 for ; Tue, 27 Nov 2018 10:20:29 -0500 (EST) Received: by mail-wm1-f70.google.com with SMTP id g3so3715332wmf.1 for ; Tue, 27 Nov 2018 07:20:29 -0800 (PST) Received: from unicorn.mansr.com (unicorn.mansr.com. [2001:8b0:ca0d:8d8e::2]) by mx.google.com with ESMTPS id q184-v6si3323643wma.41.2018.11.27.07.20.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 27 Nov 2018 07:20:27 -0800 (PST) From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= 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: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox Cc: linux-mm@kvack.org, 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") accidenta= lly >> 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. --=20 M=E5ns Rullg=E5rd