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 8546DC02182 for ; Mon, 20 Jan 2025 13:59:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1B0A3280006; Mon, 20 Jan 2025 08:59:09 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1609C280002; Mon, 20 Jan 2025 08:59:09 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 027F4280006; Mon, 20 Jan 2025 08:59:08 -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 D3E42280002 for ; Mon, 20 Jan 2025 08:59:08 -0500 (EST) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 8FBAD120160 for ; Mon, 20 Jan 2025 13:59:08 +0000 (UTC) X-FDA: 83027986776.07.A60730F Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf16.hostedemail.com (Postfix) with ESMTP id 082C7180003 for ; Mon, 20 Jan 2025 13:59:06 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Tu7cbzt1; spf=pass (imf16.hostedemail.com: domain of a.hindborg@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=a.hindborg@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1737381547; 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=6uRtkk/jNvzKOVauU8wC20bjjcc2C00m8OjNWM7tFjo=; b=3s/ltn5rRvUVvV6UtE1gbZD+Q8O/iC+eHb4fvIwhWNzSTIZgFvqqHQUqCrAz8AIzTMQVsw uZBDE42MAnWCObM9AEPfHE+/ioEEH9YEiv0wU4DmBJlvabPKUnAUGNKNQ3FMnbeAZ3mzbp VsTocJztPjbawgZHpasW2SKgM2EbiUc= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1737381547; a=rsa-sha256; cv=none; b=m1c/jCoJ/fv6l2O/vT1diqxLmTPSyJwxjFSG9Im9a2asDgame1OE1HZ6yAFem5y2wPi9f4 vFB1bzPW+UBrd7+89QrfJk5PLF6FSNe3PoyC1UbhymksHFvHiGhpro0JHAIisWXCgoyNVx aUXSl5Avhnb0HPoYD9pR+5v4/xhT9dg= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Tu7cbzt1; spf=pass (imf16.hostedemail.com: domain of a.hindborg@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=a.hindborg@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 0FEBF5C06A8; Mon, 20 Jan 2025 13:58:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 536D5C4CEE1; Mon, 20 Jan 2025 13:59:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737381544; bh=6uRtkk/jNvzKOVauU8wC20bjjcc2C00m8OjNWM7tFjo=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=Tu7cbzt1EYuVAHA7GxMhtAmbSMfoFckIjtgp+uyQyHh/OaWqjISsRZFOk2Csc6PV+ OWKowypmWsZ5nn0XAicZUW4Z91indymLBUoZaS/ZXOfpDU+EhSCtlf/1EGAfe/2gTN iH2Fi2kgTSrjrtJtR+ZJOp8aU7Efaodq3FoGhTiutWu/TKExCcCv4VlyoONEiUrfT+ AuadReex7reNrERMSeFkdpeJfU/hSoR7aDyUmCVoyaqfr59LH0m0L70pW6whX06BFQ 8brt8PrxGB8tOQAO3D1KtYZUCF5IJ4FP31eKs1cd+NaSkOc4gOXyQmtmZjKrkA6zip 5zu17SqiH45JQ== From: Andreas Hindborg To: "Alice Ryhl" Cc: "Miguel Ojeda" , "Matthew Wilcox" , "Lorenzo Stoakes" , "Vlastimil Babka" , "John Hubbard" , "Liam R. Howlett" , "Andrew Morton" , "Greg Kroah-Hartman" , "Arnd Bergmann" , "Jann Horn" , "Suren Baghdasaryan" , "Alex Gaynor" , "Boqun Feng" , "Gary Guo" , =?utf-8?Q?Bj?= =?utf-8?Q?=C3=B6rn?= Roy Baron , "Benno Lossin" , "Trevor Gross" , , , Subject: Re: [PATCH v12 4/8] mm: rust: add lock_vma_under_rcu In-Reply-To: <20250115-vma-v12-4-375099ae017a@google.com> (Alice Ryhl's message of "Wed, 15 Jan 2025 13:35:07 +0000") References: <20250115-vma-v12-0-375099ae017a@google.com> <20250115-vma-v12-4-375099ae017a@google.com> User-Agent: mu4e 1.12.7; emacs 29.4 Date: Mon, 20 Jan 2025 13:50:42 +0100 Message-ID: <87tt9td4yl.fsf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain X-Stat-Signature: rfo1fiqsu77krp75wg5hayzgj1r1t7t6 X-Rspam-User: X-Rspamd-Queue-Id: 082C7180003 X-Rspamd-Server: rspam03 X-HE-Tag: 1737381546-482184 X-HE-Meta: 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 1nM4Io2z FdTCFaDl0F7pu8BcTW3YiiRavdkI+loE2EJqhntWt4GAqAjUABMuYo+/UWfroYguFmbuM+fJKqP1aQA4dt6c0OQjeqFBr33Iy3X6efqgfMfh57zYG9YjLQnG/mvIoXy1Q2vU37o8sMbWPiqmcI0EQPeYTK9gBaKKFcbcPLFohRvfJJvLKsJUeRO21cIl6a1YosRtL7HBLZ6XO4dnfnZzSJhW6jirEh+K1LhFtxcwoL5/jb16yCy8f6NHiR7YSqTlGLEsvHuQqzeD/Qr51rZLJdsqdWaBFozRvRyTGkvN890iZ+6yAxo6QgnIbphh4oN67eU84B3MotW7O2ac6IUahnTeAy3HpyOWIYOykawpHLPyLNR8= X-Bogosity: Unsure, tests=bogofilter, spamicity=0.457298, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: "Alice Ryhl" writes: > Currently, the binder driver always uses the mmap lock to make changes > to its vma. Because the mmap lock is global to the process, this can > involve significant contention. However, the kernel has a feature called > per-vma locks, which can significantly reduce contention. For example, > you can take a vma lock in parallel with an mmap write lock. This is > important because contention on the mmap lock has been a long-term > recurring challenge for the Binder driver. > > This patch introduces support for using `lock_vma_under_rcu` from Rust. > The Rust Binder driver will be able to use this to reduce contention on > the mmap lock. > > Acked-by: Lorenzo Stoakes (for mm bits) > Reviewed-by: Jann Horn > Signed-off-by: Alice Ryhl Reviewed-by: Andreas Hindborg Best regards, Andreas Hindborg