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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5A53C5479D for ; Wed, 11 Jan 2023 14:15:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 319BD8E0007; Wed, 11 Jan 2023 09:15:09 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2C9BE8E0001; Wed, 11 Jan 2023 09:15:09 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 16A5C8E0007; Wed, 11 Jan 2023 09:15:09 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 074CE8E0001 for ; Wed, 11 Jan 2023 09:15:09 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id B4C3D16063F for ; Wed, 11 Jan 2023 14:15:08 +0000 (UTC) X-FDA: 80342715096.30.AE36D94 Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) by imf05.hostedemail.com (Postfix) with ESMTP id A3C6A100002 for ; Wed, 11 Jan 2023 14:15:06 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=shutemov.name header.s=fm1 header.b=BIBP0klk; dkim=pass header.d=messagingengine.com header.s=fm3 header.b=WEISMpVy; spf=pass (imf05.hostedemail.com: domain of kirill@shutemov.name designates 66.111.4.28 as permitted sender) smtp.mailfrom=kirill@shutemov.name; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1673446506; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=d7o3kj/Z/vK6V725jjEnUNSDO4G71V9PXMP9Obm3o9M=; b=4BIqUy71CVqLtu/o8NQT8Sahc8pFdA/mH71wk4Bf40pCiSoKPNhkbfeHO+LCY6E59jQlYR Ug/IdhfBI46I0O18eOp4Y2MNHLRlNchJ1vYHsgmtazArNveqSna2C9U2uaKBZzQoUucdGV cCdsVfjFSb7mhrzpaReJayp4jZKY9e8= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=shutemov.name header.s=fm1 header.b=BIBP0klk; dkim=pass header.d=messagingengine.com header.s=fm3 header.b=WEISMpVy; spf=pass (imf05.hostedemail.com: domain of kirill@shutemov.name designates 66.111.4.28 as permitted sender) smtp.mailfrom=kirill@shutemov.name; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1673446506; a=rsa-sha256; cv=none; b=n3La49a5GTDRJ/hG43YDuJ05P+PxJwhft81SHR769SLhN79Pu0rtqbZ6884Jhtsty4ykRg IwNnR/EKOSFdRGjgxRmu8kI0XvvZdXD8eS+j+hEdgNBCp7XYGdJOdME3ZdpYli6CZ1qj2l a9DCz6DoX3Ye8mzaNDwkp6e4+i9CxzE= Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.nyi.internal (Postfix) with ESMTP id 85C315C01BD; Wed, 11 Jan 2023 09:15:04 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute5.internal (MEProxy); Wed, 11 Jan 2023 09:15:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov.name; h=cc:cc:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm1; t=1673446504; x=1673532904; bh=d7 o3kj/Z/vK6V725jjEnUNSDO4G71V9PXMP9Obm3o9M=; b=BIBP0klkoRyawjatsO AHvzRWMjsOBzYHjzWRyVjft3peKFivD3em4OKL4nJEoaxnXIIesdzTdkklwCRqxz T2zX6osIT8LYDsp01viXrHe87sgNjGzIDB5HdZrkebdAbUX3rLjG7a5q8GTL+Hj1 AT30h0moP6fGfucn/1cLOTQhaMxQiA2NdGk/sJKUpqR34Ccb1cAfQ90BBq0/9uMl ai96qkrUYfXEuZa2vy0pqD2FM2yoMJ+zmx1rCQ9pIZHmWrZl/lumbDVaVfE0Kxi7 eowGxF9xS4yKTEAGFXTxWJmshrG5xt8rznCjQhD46sbXq5Y7L+i8hUZ3uDlXZ/HA 3v1A== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:feedback-id :feedback-id:from:from:in-reply-to:in-reply-to:message-id :mime-version:references:reply-to:sender:subject:subject:to:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm3; t=1673446504; x=1673532904; bh=d7o3kj/Z/vK6V725jjEnUNSDO4G7 1V9PXMP9Obm3o9M=; b=WEISMpVytYlaMYfejIvTKo2aTBvvJmU+AG/y83yE7Vaa o74pBAens5T71FO91s9aqU3laRruA/dEFjBt8+RTMbY5pT6YzfPEW9jEmihGvkxQ xH2U7fLSoZd7AHf6UCIO+frsOZiuixWz6n2jtp5/vEE968vmHB3tNLqZBOEV50i6 VDYlPepDCAKPjOjDuoGy5qNCltb2NW0O5G0oK9byTllLzjtBbPEROiZ8Lp+s1v30 Wji/YCxQRDsEFCdZivBi6WHyg2y6k7jAmJRwrgwJbajrVAooDOJxxkJatvVGkT1a iw+/HL/9F7rvnOc8ztbhYLBxuj+TqU42dNnzmFqtjw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrleeggdeivdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpeffhffvvefukfhfgggtuggjsehttddttddttddvnecuhfhrohhmpedfmfhirhhi lhhlucetrdcuufhhuhhtvghmohhvfdcuoehkihhrihhllhesshhhuhhtvghmohhvrdhnrg hmvgeqnecuggftrfgrthhtvghrnhephfeigefhtdefhedtfedthefghedutddvueehtedt tdehjeeukeejgeeuiedvkedtnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpe hmrghilhhfrhhomhepkhhirhhilhhlsehshhhuthgvmhhovhdrnhgrmhgv X-ME-Proxy: Feedback-ID: ie3994620:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 11 Jan 2023 09:15:03 -0500 (EST) Received: by box.shutemov.name (Postfix, from userid 1000) id A4689104377; Wed, 11 Jan 2023 17:14:59 +0300 (+03) Date: Wed, 11 Jan 2023 17:14:59 +0300 From: "Kirill A. Shutemov" To: Linus Torvalds Cc: "Kirill A. Shutemov" , Dave Hansen , Andy Lutomirski , Peter Zijlstra , the arch/x86 maintainers , Kostya Serebryany , Andrey Ryabinin , Andrey Konovalov , Alexander Potapenko , Taras Madan , Dmitry Vyukov , "H . J . Lu" , Andi Kleen , Rick Edgecombe , Bharata B Rao , Jacob Pan , Ashok Raj , Linux-MM , Linux Kernel Mailing List Subject: Re: [PATCHv14 04/17] x86/mm: Handle LAM on context switch Message-ID: <20230111141459.ah7ijfbm733c4g7m@box.shutemov.name> References: <20230111123736.20025-1-kirill.shutemov@linux.intel.com> <20230111123736.20025-5-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: A3C6A100002 X-Stat-Signature: 48wtn9k4ijcsaaoewxt8t3cr95unm4n8 X-HE-Tag: 1673446506-149197 X-HE-Meta: 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 eAtNNrCC DSBn1L/BCj+1K6SauRY5rC3CD7zsr30CNOzYIdIr6fCdDoqw= 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 Wed, Jan 11, 2023 at 07:49:30AM -0600, Linus Torvalds wrote: > Sorry, I'm traveling, and right now only on mobile. So I'm reading patches > on my phone, and answering on it too, so html garbage.. > > On Wed, Jan 11, 2023, 07:24 Kirill A. Shutemov < > kirill.shutemov@linux.intel.com> wrote: > > > > > +static inline unsigned long mm_lam_cr3_mask(struct mm_struct *mm) > > +{ > > + return READ_ONCE(mm->context.lam_cr3_mask); > > +} > > > > I mentioned this before - in the original version this needed (but didn't > have, iirc) that READ_ONCE, but in the new non-thread situation I don't > think that's true. There should be no concurrent changes that can interfere > with the read, no? It should be safe, yes. It is reachable from iommu_sva_bind_device(), but it only called with mm == current->mm. I will drop the READ_ONCE(). -- Kiryl Shutsemau / Kirill A. Shutemov