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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 033B7C06513 for ; Wed, 3 Jul 2019 17:22:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D242221882 for ; Wed, 3 Jul 2019 17:22:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="o4SEJPOO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727272AbfGCRW2 (ORCPT ); Wed, 3 Jul 2019 13:22:28 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:14102 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726721AbfGCRW2 (ORCPT ); Wed, 3 Jul 2019 13:22:28 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Wed, 03 Jul 2019 10:22:23 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Wed, 03 Jul 2019 10:22:27 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Wed, 03 Jul 2019 10:22:27 -0700 Received: from rcampbell-dev.nvidia.com (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 3 Jul 2019 17:22:23 +0000 Subject: Re: [PATCH 18/22] mm: return valid info from hmm_range_unregister To: Christoph Hellwig , Dan Williams , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Jason Gunthorpe , Ben Skeggs CC: Ira Weiny , , , , , , References: <20190701062020.19239-1-hch@lst.de> <20190701062020.19239-19-hch@lst.de> X-Nvconfidentiality: public From: Ralph Campbell Message-ID: <0cc37cca-4f3a-40bb-0059-bf3880c171b8@nvidia.com> Date: Wed, 3 Jul 2019 10:22:23 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190701062020.19239-19-hch@lst.de> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL104.nvidia.com (172.18.146.11) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1562174544; bh=t4iv+JkVQXMDn9U21ZE8onfcueQ7442WkhT3/Dcpa4M=; h=X-PGP-Universal:Subject:To:CC:References:X-Nvconfidentiality:From: Message-ID:Date:User-Agent:MIME-Version:In-Reply-To: X-Originating-IP:X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=o4SEJPOOrRcVRLndEm7Zo7kTSy5FZf0UU7cSYb6tblR8H1EUMVX5E/0FjYzJrSpko wz/tUydScQzFM1TJuHIP9tIFH+twnUQBk37KA0HVngw9EftV5QqHG2Tqfjp2J8EPuI cOTG6KhoZMk2Kh1KQh0nP3AEh0uE4jVMnBYCBTkXTdSVmN+wIcMvLmh+GM9psOeZBs 3aY56IDBUR2I0RSrHwqu9wiz9+2bNfCk3CTpCrQB/Pq2QpA4D4k/ASPiYqwdt5SsHr E0w4jAe1UNn6ayNyaW96+0ynvEfH+IEp7CDyfnUEVKIhxGZ7F5A0JKPp7wK4+C0AuG 0J+QqvUEgD4RQ== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/30/19 11:20 PM, Christoph Hellwig wrote: > Checking range->valid is trivial and has no meaningful cost, but > nicely simplifies the fastpath in typical callers. Also remove the > hmm_vma_range_done function, which now is a trivial wrapper around > hmm_range_unregister. > > Signed-off-by: Christoph Hellwig Reviewed-by: Ralph Campbell > --- > drivers/gpu/drm/nouveau/nouveau_svm.c | 2 +- > include/linux/hmm.h | 11 +---------- > mm/hmm.c | 6 +++++- > 3 files changed, 7 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c > index 8c92374afcf2..9d40114d7949 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_svm.c > +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c > @@ -652,7 +652,7 @@ nouveau_svm_fault(struct nvif_notify *notify) > ret = hmm_vma_fault(&svmm->mirror, &range, true); > if (ret == 0) { > mutex_lock(&svmm->mutex); > - if (!hmm_vma_range_done(&range)) { > + if (!hmm_range_unregister(&range)) { > mutex_unlock(&svmm->mutex); > goto again; > } > diff --git a/include/linux/hmm.h b/include/linux/hmm.h > index 0fa8ea34ccef..4b185d286c3b 100644 > --- a/include/linux/hmm.h > +++ b/include/linux/hmm.h > @@ -465,7 +465,7 @@ int hmm_range_register(struct hmm_range *range, > unsigned long start, > unsigned long end, > unsigned page_shift); > -void hmm_range_unregister(struct hmm_range *range); > +bool hmm_range_unregister(struct hmm_range *range); > long hmm_range_snapshot(struct hmm_range *range); > long hmm_range_fault(struct hmm_range *range, bool block); > long hmm_range_dma_map(struct hmm_range *range, > @@ -487,15 +487,6 @@ long hmm_range_dma_unmap(struct hmm_range *range, > */ > #define HMM_RANGE_DEFAULT_TIMEOUT 1000 > > -/* This is a temporary helper to avoid merge conflict between trees. */ > -static inline bool hmm_vma_range_done(struct hmm_range *range) > -{ > - bool ret = hmm_range_valid(range); > - > - hmm_range_unregister(range); > - return ret; > -} > - > /* This is a temporary helper to avoid merge conflict between trees. */ > static inline int hmm_vma_fault(struct hmm_mirror *mirror, > struct hmm_range *range, bool block) > diff --git a/mm/hmm.c b/mm/hmm.c > index de35289df20d..c85ed7d4e2ce 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -920,11 +920,14 @@ EXPORT_SYMBOL(hmm_range_register); > * > * Range struct is used to track updates to the CPU page table after a call to > * hmm_range_register(). See include/linux/hmm.h for how to use it. > + * > + * Returns if the range was still valid at the time of unregistering. Since this is an exported function, we should have kernel-doc comments. That is probably a separate patch but at least this line could be: Return: True if the range was still valid at the time of unregistering. > */ > -void hmm_range_unregister(struct hmm_range *range) > +bool hmm_range_unregister(struct hmm_range *range) > { > struct hmm *hmm = range->hmm; > unsigned long flags; > + bool ret = range->valid; > > spin_lock_irqsave(&hmm->ranges_lock, flags); > list_del_init(&range->list); > @@ -941,6 +944,7 @@ void hmm_range_unregister(struct hmm_range *range) > */ > range->valid = false; > memset(&range->hmm, POISON_INUSE, sizeof(range->hmm)); > + return ret; > } > EXPORT_SYMBOL(hmm_range_unregister); > >