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spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2A1BD6B0003; Thu, 19 Mar 2020 21:33:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 251116B0006; Thu, 19 Mar 2020 21:33:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 140586B0007; Thu, 19 Mar 2020 21:33:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0189.hostedemail.com [216.40.44.189]) by kanga.kvack.org (Postfix) with ESMTP id EF8E46B0003 for ; Thu, 19 Mar 2020 21:33:09 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id C8A2A5820 for ; Fri, 20 Mar 2020 01:33:09 +0000 (UTC) X-FDA: 76614017298.25.prose07_8ff478880ec1a X-HE-Tag: prose07_8ff478880ec1a X-Filterd-Recvd-Size: 4844 Received: from hqnvemgate24.nvidia.com (hqnvemgate24.nvidia.com [216.228.121.143]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Fri, 20 Mar 2020 01:33:09 +0000 (UTC) Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 19 Mar 2020 18:31:29 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 19 Mar 2020 18:33:07 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 19 Mar 2020 18:33:07 -0700 Received: from rcampbell-dev.nvidia.com (172.20.13.39) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Fri, 20 Mar 2020 01:33:07 +0000 Subject: Re: [PATCH 3/4] mm: simplify device private page handling in hmm_range_fault To: Jason Gunthorpe CC: Christoph Hellwig , Dan Williams , Bharata B Rao , =?UTF-8?Q?Christian_K=c3=b6nig?= , Ben Skeggs , Jerome Glisse , , , , , References: <20200316193216.920734-1-hch@lst.de> <20200316193216.920734-4-hch@lst.de> <7256f88d-809e-4aba-3c46-a223bd8cc521@nvidia.com> <20200317121536.GQ20941@ziepe.ca> <20200317122445.GA11662@lst.de> <20200317122813.GA11866@lst.de> <20200317124755.GR20941@ziepe.ca> <20200317125955.GA12847@lst.de> <24fca825-3b0f-188f-bcf2-fadcf3a9f05a@nvidia.com> <20200320001428.GA9199@ziepe.ca> X-Nvconfidentiality: public From: Ralph Campbell Message-ID: <8d549ef6-14ae-7055-58c8-d56de8bf4ba6@nvidia.com> Date: Thu, 19 Mar 2020 18:33:04 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200320001428.GA9199@ziepe.ca> X-Originating-IP: [172.20.13.39] X-ClientProxiedBy: HQMAIL107.nvidia.com (172.20.187.13) 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=1584667889; bh=0XrmkYqlA+KPtFLXc9j6McuShC8myf+16OYVMSLPN98=; 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=q8yRQ8OgBCDzsDjIi7BZWgW2W6wpR+FQ9bo0pOdEKoDHdimpX9OlV1kxhTKGxCsdK y7oGNmhxCYODXGZbFeJdZEagt9ppPLakBoNElC0LiRiYd/f4G5cClYDE/oM846Gca1 m+mW8C4/i21sEKSuLvhfqFle1bJELFzb9iAxvgXvYXuG3ISf6g1cRwlGQeREzIY+MB VkbG0wNleCaEdDy/5biJSdif8WCwBTrVsrsENIUiCRuDE8RrpgajhsBXiSiJfJ7RGp ropfu4FvhZlxXPEZ7zcifJz6ZW7mhcjktbl6+ToyvLn0TCLionmVu5NS2mntJg0+e0 M+COmpAgYcPfA== 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 3/19/20 5:14 PM, Jason Gunthorpe wrote: > On Tue, Mar 17, 2020 at 04:14:31PM -0700, Ralph Campbell wrote: > >> +static int dmirror_fault(struct dmirror *dmirror, unsigned long start, >> + unsigned long end, bool write) >> +{ >> + struct mm_struct *mm = dmirror->mm; >> + unsigned long addr; >> + uint64_t pfns[64]; >> + struct hmm_range range = { >> + .notifier = &dmirror->notifier, >> + .pfns = pfns, >> + .flags = dmirror_hmm_flags, >> + .values = dmirror_hmm_values, >> + .pfn_shift = DPT_SHIFT, >> + .pfn_flags_mask = ~(dmirror_hmm_flags[HMM_PFN_VALID] | >> + dmirror_hmm_flags[HMM_PFN_WRITE]), > > Since pfns is not initialized pfn_flags_mask should be 0. Good point. >> + .default_flags = dmirror_hmm_flags[HMM_PFN_VALID] | >> + (write ? dmirror_hmm_flags[HMM_PFN_WRITE] : 0), >> + .dev_private_owner = dmirror->mdevice, >> + }; >> + int ret = 0; > >> +static int dmirror_snapshot(struct dmirror *dmirror, >> + struct hmm_dmirror_cmd *cmd) >> +{ >> + struct mm_struct *mm = dmirror->mm; >> + unsigned long start, end; >> + unsigned long size = cmd->npages << PAGE_SHIFT; >> + unsigned long addr; >> + unsigned long next; >> + uint64_t pfns[64]; >> + unsigned char perm[64]; >> + char __user *uptr; >> + struct hmm_range range = { >> + .pfns = pfns, >> + .flags = dmirror_hmm_flags, >> + .values = dmirror_hmm_values, >> + .pfn_shift = DPT_SHIFT, >> + .pfn_flags_mask = ~0ULL, > > Same here, especially since this is snapshot > > Jason Actually, snapshot ignores pfn_flags_mask and default_flags. In hmm_pte_need_fault(), HMM_FAULT_SNAPSHOT is checked and returns early before checking pfn_flags_mask and default_flags since no faults are being requested.