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 C79DFC48BF6 for ; Thu, 29 Feb 2024 15:56:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5FEF66B0099; Thu, 29 Feb 2024 10:56:40 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5AF3A6B009B; Thu, 29 Feb 2024 10:56:40 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 477326B009C; Thu, 29 Feb 2024 10:56:40 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 35DB76B0099 for ; Thu, 29 Feb 2024 10:56:40 -0500 (EST) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id DA5621A013E for ; Thu, 29 Feb 2024 15:56:39 +0000 (UTC) X-FDA: 81845294118.16.20415E5 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf08.hostedemail.com (Postfix) with ESMTP id 8254016001C for ; Thu, 29 Feb 2024 15:56:36 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=MyDA82W9; spf=none (imf08.hostedemail.com: domain of BATV+ba4d12e182ac9dd248a8+7494+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+ba4d12e182ac9dd248a8+7494+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1709222197; 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=ZZeeQhzP/DHpKF5QdT9LDfZVh1KeLzxu5kAiu8X0IuI=; b=Xo9DFsTHWvPqMjHwb8SrfRBUklVfn72ydDr3wgE6cfVwY4ZLsUdQWURMNzxuIQsWY+YuCR fFdkpAczkWUTdwnGfVa1mn/1CnXPIrlQFKYL+pDulh9UZxGjR63Rgy1v6dT0EZF4MyYFR1 kY5YEhY3SUcZCPmITr2+3p7uDo/0MXE= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1709222197; a=rsa-sha256; cv=none; b=3VtLCbqCGyHaArmy6SwX/YpVBVqC97Cqvw7NClMFIfhU6Ycd00RR3d2ufWo+A4t7ON50rs /qN5/W1P6hY0guSV+BEdGUhQzLSWmmk+isEsM5ftuu3Y5DAaO+X2+3LwUJmZFHLANHCeW/ xabIb6L5y8aQ48MW3cmeVC4lWdrSK08= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=MyDA82W9; spf=none (imf08.hostedemail.com: domain of BATV+ba4d12e182ac9dd248a8+7494+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+ba4d12e182ac9dd248a8+7494+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ZZeeQhzP/DHpKF5QdT9LDfZVh1KeLzxu5kAiu8X0IuI=; b=MyDA82W9Ybj19i6XFkxtLJHcIj DIdV0B551cX9Of1vbLiE7wQyZ+QZ5s8/rx8PcMT7ZPqE5MxTVE1PqdqAGpoLtaEP7Z4GODcSqBYpf +5PUuQblRp6R9otKcB2rgpT/TckK30wW/x9kWHfBUBOEYLAv9ENYNYjr74JbVv+4HkHvDmFDcyos1 L5Gi5pVl5ETAKTSF6e0VODoCUz2lHFEdWX18oSiBxUvU0VJHDtUoU+XqIK7UWxX26b+RFFj8q7AE8 7UYQl/Ts9ehrXAidDb+ChLkR4jo9tWvXsBvM8DXn+wWbhjnOn95vr0rgW5lmvfOKAFxXuYbK3wwqj Ze2WUX/Q==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1rfilp-0000000E9xh-2JaC; Thu, 29 Feb 2024 15:56:29 +0000 Date: Thu, 29 Feb 2024 07:56:29 -0800 From: Christoph Hellwig To: Alexei Starovoitov Cc: Christoph Hellwig , bpf , Daniel Borkmann , Andrii Nakryiko , Linus Torvalds , Barret Rhoden , Johannes Weiner , Lorenzo Stoakes , Andrew Morton , Uladzislau Rezki , Boris Ostrovsky , sstabellini@kernel.org, Juergen Gross , linux-mm , xen-devel@lists.xenproject.org, Kernel Team Subject: Re: [PATCH v2 bpf-next 3/3] mm: Introduce VM_SPARSE kind and vm_area_[un]map_pages(). 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See http://www.infradead.org/rpr.html X-Rspamd-Queue-Id: 8254016001C X-Rspam-User: X-Stat-Signature: wxku3ayg8ggh5m5cya7x1bzi8ir4bptx X-Rspamd-Server: rspam03 X-HE-Tag: 1709222196-777112 X-HE-Meta: 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 PoTbBWaB 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 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: List-Subscribe: List-Unsubscribe: On Tue, Feb 27, 2024 at 05:31:28PM -0800, Alexei Starovoitov wrote: > What would it look like with a cookie? > A static inline wrapper around get_vm_area() that returns area->addr ? > And the start address of vmap range will be such a cookie? Hmm, just making the kernel virtual address the cookie actually sounds pretty neat indeed even if I did not have that in mind. > I guess I don't understand the motivation to hide 'struct vm_struct *'. The prime reason is that then people will try to start random APIs that work on it. But let's give it a try without the wrappers and see how things go.