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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,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 C50F7C2BCA1 for ; Fri, 7 Jun 2019 18:25:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 732CC208E3 for ; Fri, 7 Jun 2019 18:24:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="Jzl10aMI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 732CC208E3 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 6D6996B000C; Fri, 7 Jun 2019 14:24:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 686796B000E; Fri, 7 Jun 2019 14:24:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 575A26B0266; Fri, 7 Jun 2019 14:24:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-yb1-f200.google.com (mail-yb1-f200.google.com [209.85.219.200]) by kanga.kvack.org (Postfix) with ESMTP id 39E876B000C for ; Fri, 7 Jun 2019 14:24:49 -0400 (EDT) Received: by mail-yb1-f200.google.com with SMTP id v15so2745053ybe.13 for ; Fri, 07 Jun 2019 11:24:49 -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=xt8hRcHzLeQkLBeS1/P3+kfd7HxoS8TOq54zYdn437c=; b=d8J7I0uABBb6BA0QHinYRXXScO/QQ1Cb2/O8a9bMLMtXnRxwuHn4z+O3/VDkPD6/3c pOGj1eUU8vH3UYQhene234Do+FQgNOccImgzUZsWXVdjh9+qC1dxo/X5/WTV/GofCpRN 7Eg7wTmtp52zGRTreLE/zid6NFHE/+ZQNnS4dL9P0s1eIcSSGhYeAG2TsDZYTlzg+87M oJHuYqHr1mPnuIYyDj/RsqlYGivbAkYPnJZAgnRP+H+DzfYDSeeKibDR0afesh5Jq+yC VWaNhbRXmQDV5pMgw6Y42RbKtBEjRF85EaRLlK/jwmjxr+1RSEXqUubCmua9yeZWlMtN LTBQ== X-Gm-Message-State: APjAAAXOhLb5nZ/vR3HHKIqeG/CHoLFTRgbZD9HwekTzLWJmLrXD0778 t2Jcqamqb/tyrsb3AuaA2RsnPDG2J68Hq/SYxKoISxhnOWSK4u51feO7qgkL/W1GAKBs8rStfja YXB3i8LUzHwIK26ntgwOD7icLmp/VhQ8ce9y1guT46eIGy1Zq0HuesduJ0cch2sXIQg== X-Received: by 2002:a25:cc0f:: with SMTP id l15mr17163788ybf.506.1559931889014; Fri, 07 Jun 2019 11:24:49 -0700 (PDT) X-Google-Smtp-Source: APXvYqwGI3Wqj9gKemj3bspraDvj5AQufBeowxWfxr1rY301h9aaK5+5I2QHVboEXUC8jJGWyMXE X-Received: by 2002:a25:cc0f:: with SMTP id l15mr17163752ybf.506.1559931888345; Fri, 07 Jun 2019 11:24:48 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1559931888; cv=none; d=google.com; s=arc-20160816; b=bs68sCrraSCGKstvtdKHEFBlM3VyNAoxkmjrX58JuTr6Nz7fIMrnQbwvUwT0GefnST pqQCRqVIY0p4vjaaBEdtV78oeSATs5MTUuQiNUAHJPG+ziWxpWsP+nuCvpGl3LlXALno fwoIcmymgHf/aQF1YoZ7YgHdt0mD6RUwx2w++SgFSAwBuuUykTmZErSlOk4euR0RnAFf zaqihQZ//7D0oGDgFKTMkXA+PCNZfpYp7MURII+QIXuaC7tbKHa+Q8CZaexWhNv71p6N PAQdg+YruwRft0cB94Ff9HFS32RJ+uTMptv48MCNqDQaGlW4WV0MT4DOfKUquJ66gYYB YZMA== 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=xt8hRcHzLeQkLBeS1/P3+kfd7HxoS8TOq54zYdn437c=; b=hReUR5JJfGxCQI29na4oxMfd67X+JoTwFSvpWuJB30cS75+j1BMkAFZwOePRihbK9P 9auBejOdvleVTcvc8RyQIB4iJKYIyVbrX1NvfuGd5OiddaTsDZqlKbEXmHaI8SB14ZmF cEyzcv9ZgGg/I3wf/lIDdr6FkJYkTiHdn+p3rPWRsoQQltpQjevuZ+UFB5TRip9uy1aZ 9LM36R6ti/mhkCxDTjedNAdvtiea5zMYdpsPO0Xa7uMFSnGoQ1AoJe0DxDgn9p4X8kxF RW4FfDj1F+9OireES1cEZgmO4dK4W2szySTaKaMDhy7Q+3kxk5nWyVzUxi86JyrcfNi0 QKeA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@nvidia.com header.s=n1 header.b=Jzl10aMI; spf=pass (google.com: domain of rcampbell@nvidia.com designates 216.228.121.65 as permitted sender) smtp.mailfrom=rcampbell@nvidia.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com Received: from hqemgate16.nvidia.com (hqemgate16.nvidia.com. [216.228.121.65]) by mx.google.com with ESMTPS id o11si725151ywm.41.2019.06.07.11.24.48 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 07 Jun 2019 11:24:48 -0700 (PDT) Received-SPF: pass (google.com: domain of rcampbell@nvidia.com designates 216.228.121.65 as permitted sender) client-ip=216.228.121.65; Authentication-Results: mx.google.com; dkim=pass header.i=@nvidia.com header.s=n1 header.b=Jzl10aMI; spf=pass (google.com: domain of rcampbell@nvidia.com designates 216.228.121.65 as permitted sender) smtp.mailfrom=rcampbell@nvidia.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Fri, 07 Jun 2019 11:24:47 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Fri, 07 Jun 2019 11:24:47 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Fri, 07 Jun 2019 11:24:47 -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; Fri, 7 Jun 2019 18:24:44 +0000 Subject: Re: [PATCH v2 hmm 02/11] mm/hmm: Use hmm_mirror not mm as an argument for hmm_range_register To: Jason Gunthorpe , Jerome Glisse , "John Hubbard" , CC: , , Andrea Arcangeli , , , Jason Gunthorpe References: <20190606184438.31646-1-jgg@ziepe.ca> <20190606184438.31646-3-jgg@ziepe.ca> X-Nvconfidentiality: public From: Ralph Campbell Message-ID: <4a391bd4-287c-5f13-3bca-c6a46ff8d08c@nvidia.com> Date: Fri, 7 Jun 2019 11:24:44 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.0 MIME-Version: 1.0 In-Reply-To: <20190606184438.31646-3-jgg@ziepe.ca> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL108.nvidia.com (172.18.146.13) 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=1559931887; bh=xt8hRcHzLeQkLBeS1/P3+kfd7HxoS8TOq54zYdn437c=; 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=Jzl10aMIEyNyvMJQOea9/cem8BK3fdX7N7BBW39ZQ2ZTnhr3i9Bg45PYwohda1UY9 LkcU8MB8OKdUMSj8b6yUghIjjinGIugW4aSBllEIx7TVCfwzbApXGQL3P9ClD/AN2z Yv3rNjAyUFe/mSLyYvWlzlYj8psKbq2qMRJzEB+cKi7ZRC9AQCwhtNhX/CDYSmifhd OgQAo1Xs1VMOWXccxd1U6MRqnzkHVOsG3cy4I45UtG8jiXu1hu6emUv1Z1CwQxFrGP /0qhySFwJdt1mao3BY0IXnmpWfz2Fu3UMQQ3D0H/L5X1ETwrAIQVgVzM8gB201RZnz ZlKK89hwVr+aw== 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 6/6/19 11:44 AM, Jason Gunthorpe wrote: > From: Jason Gunthorpe > > Ralph observes that hmm_range_register() can only be called by a driver > while a mirror is registered. Make this clear in the API by passing in the > mirror structure as a parameter. > > This also simplifies understanding the lifetime model for struct hmm, as > the hmm pointer must be valid as part of a registered mirror so all we > need in hmm_register_range() is a simple kref_get. > > Suggested-by: Ralph Campbell > Signed-off-by: Jason Gunthorpe You might CC Ben for the nouveau part. CC: Ben Skeggs Reviewed-by: Ralph Campbell > --- > v2 > - Include the oneline patch to nouveau_svm.c > --- > drivers/gpu/drm/nouveau/nouveau_svm.c | 2 +- > include/linux/hmm.h | 7 ++++--- > mm/hmm.c | 15 ++++++--------- > 3 files changed, 11 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c > index 93ed43c413f0bb..8c92374afcf227 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_svm.c > +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c > @@ -649,7 +649,7 @@ nouveau_svm_fault(struct nvif_notify *notify) > range.values = nouveau_svm_pfn_values; > range.pfn_shift = NVIF_VMM_PFNMAP_V0_ADDR_SHIFT; > again: > - ret = hmm_vma_fault(&range, true); > + ret = hmm_vma_fault(&svmm->mirror, &range, true); > if (ret == 0) { > mutex_lock(&svmm->mutex); > if (!hmm_vma_range_done(&range)) { > diff --git a/include/linux/hmm.h b/include/linux/hmm.h > index 688c5ca7068795..2d519797cb134a 100644 > --- a/include/linux/hmm.h > +++ b/include/linux/hmm.h > @@ -505,7 +505,7 @@ static inline bool hmm_mirror_mm_is_alive(struct hmm_mirror *mirror) > * Please see Documentation/vm/hmm.rst for how to use the range API. > */ > int hmm_range_register(struct hmm_range *range, > - struct mm_struct *mm, > + struct hmm_mirror *mirror, > unsigned long start, > unsigned long end, > unsigned page_shift); > @@ -541,7 +541,8 @@ static inline bool hmm_vma_range_done(struct hmm_range *range) > } > > /* This is a temporary helper to avoid merge conflict between trees. */ > -static inline int hmm_vma_fault(struct hmm_range *range, bool block) > +static inline int hmm_vma_fault(struct hmm_mirror *mirror, > + struct hmm_range *range, bool block) > { > long ret; > > @@ -554,7 +555,7 @@ static inline int hmm_vma_fault(struct hmm_range *range, bool block) > range->default_flags = 0; > range->pfn_flags_mask = -1UL; > > - ret = hmm_range_register(range, range->vma->vm_mm, > + ret = hmm_range_register(range, mirror, > range->start, range->end, > PAGE_SHIFT); > if (ret) > diff --git a/mm/hmm.c b/mm/hmm.c > index 547002f56a163d..8796447299023c 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -925,13 +925,13 @@ static void hmm_pfns_clear(struct hmm_range *range, > * Track updates to the CPU page table see include/linux/hmm.h > */ > int hmm_range_register(struct hmm_range *range, > - struct mm_struct *mm, > + struct hmm_mirror *mirror, > unsigned long start, > unsigned long end, > unsigned page_shift) > { > unsigned long mask = ((1UL << page_shift) - 1UL); > - struct hmm *hmm; > + struct hmm *hmm = mirror->hmm; > > range->valid = false; > range->hmm = NULL; > @@ -945,15 +945,12 @@ int hmm_range_register(struct hmm_range *range, > range->start = start; > range->end = end; > > - hmm = hmm_get_or_create(mm); > - if (!hmm) > - return -EFAULT; > - > /* Check if hmm_mm_destroy() was call. */ > - if (hmm->mm == NULL || hmm->dead) { > - hmm_put(hmm); > + if (hmm->mm == NULL || hmm->dead) > return -EFAULT; > - } > + > + range->hmm = hmm; > + kref_get(&hmm->kref); > > /* Initialize range to track CPU page table updates. */ > mutex_lock(&hmm->lock); >