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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D1264C4332E for ; Sat, 21 Mar 2020 08:37:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 94FCD20753 for ; Sat, 21 Mar 2020 08:37:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 94FCD20753 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 36D7F6B0007; Sat, 21 Mar 2020 04:37:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 31CF26B0008; Sat, 21 Mar 2020 04:37:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 232736B000A; Sat, 21 Mar 2020 04:37:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0056.hostedemail.com [216.40.44.56]) by kanga.kvack.org (Postfix) with ESMTP id 07C296B0007 for ; Sat, 21 Mar 2020 04:37:30 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 88AB1180AD81D for ; Sat, 21 Mar 2020 08:37:29 +0000 (UTC) X-FDA: 76618715418.17.seed68_7b97001562c3f X-HE-Tag: seed68_7b97001562c3f X-Filterd-Recvd-Size: 2545 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf44.hostedemail.com (Postfix) with ESMTP for ; Sat, 21 Mar 2020 08:37:29 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id CBF5668AFE; Sat, 21 Mar 2020 09:37:26 +0100 (CET) Date: Sat, 21 Mar 2020 09:37:26 +0100 From: Christoph Hellwig To: Jason Gunthorpe Cc: Jerome Glisse , Ralph Campbell , Felix.Kuehling@amd.com, linux-mm@kvack.org, John Hubbard , dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, Christoph Hellwig , Philip Yang , Jason Gunthorpe Subject: Re: [PATCH hmm 2/6] mm/hmm: return the fault type from hmm_pte_need_fault() Message-ID: <20200321083726.GB28695@lst.de> References: <20200320164905.21722-1-jgg@ziepe.ca> <20200320164905.21722-3-jgg@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200320164905.21722-3-jgg@ziepe.ca> User-Agent: Mutt/1.5.17 (2007-11-01) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Mar 20, 2020 at 01:49:01PM -0300, Jason Gunthorpe wrote: > +enum { > + NEED_FAULT = 1 << 0, > + NEED_WRITE_FAULT = 1 << 1, > +}; Maybe add a HMM_ prefix? > for (i = 0; i < npages; ++i) { > + required_fault |= > + hmm_pte_need_fault(hmm_vma_walk, pfns[i], cpu_flags); > + if (required_fault == (NEED_FAULT | NEED_WRITE_FAULT)) > + return required_fault; No need for the inner braces. > @@ -532,17 +515,15 @@ static int hmm_vma_walk_test(unsigned long start, unsigned long end, > */ > if ((vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP)) || > !(vma->vm_flags & VM_READ)) { > - bool fault, write_fault; > - No that there is no need for local variables I'd invert the test and return early: if ((vma->vm_flags & VM_READ) && !(vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP)) return 0; > /* > * Check to see if a fault is requested for any page in the > * range. > */ > - hmm_range_need_fault(hmm_vma_walk, range->pfns + > - ((start - range->start) >> PAGE_SHIFT), > - (end - start) >> PAGE_SHIFT, > - 0, &fault, &write_fault); > - if (fault || write_fault) > + if (hmm_range_need_fault(hmm_vma_walk, > + range->pfns + > + ((start - range->start) >> > + PAGE_SHIFT), > + (end - start) >> PAGE_SHIFT, 0)) Which should help to make this a little more readable..