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 7C9BFC0650E for ; Wed, 3 Jul 2019 17:22:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 387872189E for ; Wed, 3 Jul 2019 17:22:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="o4SEJPOO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 387872189E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C83788E000A; Wed, 3 Jul 2019 13:22:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C0BDE8E0001; Wed, 3 Jul 2019 13:22:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AAD3F8E000A; Wed, 3 Jul 2019 13:22:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) by kanga.kvack.org (Postfix) with ESMTP id 842458E0001 for ; Wed, 3 Jul 2019 13:22:29 -0400 (EDT) Received: by mail-qt1-f200.google.com with SMTP id o16so3660159qtj.6 for ; Wed, 03 Jul 2019 10:22:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding:dkim-signature; bh=t4iv+JkVQXMDn9U21ZE8onfcueQ7442WkhT3/Dcpa4M=; b=MDYPGHkTY5qgaUHPWrMsfqs96qgIgiuY5gxBGL+SJyWQ6jJ2zb6IPavKyI8Kl2vz6Q cMuVagt5LmH1nFr6Thg1LJ+0TeJFdkw+zX3NytKTENKaPozThB8Ma2p60wrAxWMgkSjn lK1jBd5L+A/o7XXkbU7+lDqhPiDUSTYxDeebbExdhKc5lpC1Gz2FyWplZLCRtrsTOABw /gbV++Vv8qgiGhOJA3JaE4sYkhVslg21ArX2P+e+1ksRTS2mvYlhihGOxCdyqRxWm+hc AHCRogqPGPFYX5zS6XVG8UEn+nGDG+pVTlzRZFBtFq113yFbboF73XCFl9BQ1GsXsbF2 o16g== X-Gm-Message-State: APjAAAVeV3Q7e6iR8SaKzG123bBujh/a0vYwt2fIDd+RDQPAqeEWCf2L VETX0kH4iXGNtV844tZH/ZHPyNk3Sf3l/nzo0OLqWf1t/ZtV58ns9V+G//ZAIOJN1ZBioLAWNOz jDUN6tEhTUEkyVfmX+w/w7XRzB/eYHZw6zKD+5cPIAnVqtGjbrBB/ZEM9X2089E0+5Q== X-Received: by 2002:a81:4c3:: with SMTP id 186mr23678473ywe.462.1562174549252; Wed, 03 Jul 2019 10:22:29 -0700 (PDT) X-Google-Smtp-Source: APXvYqzvRVtU7zgkpyVzLlHd4grFAHvvUdoNovIHbvJ8arvfCUxrMpTGmx+Wgbk9lt8CDgbFIUCf X-Received: by 2002:a81:4c3:: with SMTP id 186mr23678413ywe.462.1562174548462; Wed, 03 Jul 2019 10:22:28 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1562174548; cv=none; d=google.com; s=arc-20160816; b=QIt69/c0i/msCr9FH2y9iznmDbAAmrWU8ldgqrsvxUkBIhC1XhjvO7sAYd+zoUjL54 W4+FBBkhwq0isxB4RJjjC6WyDD9NyFGtYal08KiiR3jXnau21qfbtlFgcQyaFqVFK1FE JvzYXF1of+niGSBdGGiVeBfZiRa7Jb+vcV27H+aZMx/GrC6iehFSTuRNQ1BespielU7J GAioPoNcOqBanBUHCfDJo2tmkhOe1KP3hnlzFkVle5JCV8gbk7njFTza6/djOkuir5TU 5XSEf4jXqz+uw2FsD376nS6G4gTibfnWLuk47Y6Prx8qhKgOq2NyLe23fCZI6gpdtwN+ kz7w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=dkim-signature:content-transfer-encoding:content-language :in-reply-to:mime-version:user-agent:date:message-id:from:references :cc:to:subject; bh=t4iv+JkVQXMDn9U21ZE8onfcueQ7442WkhT3/Dcpa4M=; b=ujAFxhJpZnlwrgeHZWLVbk73SSdlitC92CTvCq3XXB4joh5zz+DMyv+cQ1h69u+PSB 4L8iKmDroooNuM3tFoEdxvX9lwnsJ4g0KPkk7PSG/LmusCOMRnC9GF7NBjX2Nw8u76uS beV4GdSs7+v4eyd0WFZ/YQKMVJbZsJ/D0jkBgmo5LY4aAeRxg7C7bGYkiH5ESiDwY8q+ 6mV3BLIxGZQ7StHGckaC4123aKJB013eM5O9N1nLX+b37k5363DjJ3JdmQm0QDyTSSHG Y4IDYxx61CpCUo88tLo4fGQ2qomDADZJJyk4hlmjpAie6DbcZm3nG+EtsxnlP5PHYNkZ LMoA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@nvidia.com header.s=n1 header.b=o4SEJPOO; spf=pass (google.com: domain of rcampbell@nvidia.com designates 216.228.121.143 as permitted sender) smtp.mailfrom=rcampbell@nvidia.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com Received: from hqemgate14.nvidia.com (hqemgate14.nvidia.com. [216.228.121.143]) by mx.google.com with ESMTPS id c200si1324584ywc.330.2019.07.03.10.22.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 Jul 2019 10:22:28 -0700 (PDT) Received-SPF: pass (google.com: domain of rcampbell@nvidia.com designates 216.228.121.143 as permitted sender) client-ip=216.228.121.143; Authentication-Results: mx.google.com; dkim=pass header.i=@nvidia.com header.s=n1 header.b=o4SEJPOO; spf=pass (google.com: domain of rcampbell@nvidia.com designates 216.228.121.143 as permitted sender) smtp.mailfrom=rcampbell@nvidia.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com 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== 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 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); > >