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 35ED2C433F5 for ; Wed, 16 Feb 2022 19:47:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 95FCC6B0071; Wed, 16 Feb 2022 14:47:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8E8EE6B0075; Wed, 16 Feb 2022 14:47:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 73C1D6B0078; Wed, 16 Feb 2022 14:47:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0213.hostedemail.com [216.40.44.213]) by kanga.kvack.org (Postfix) with ESMTP id 632506B0071 for ; Wed, 16 Feb 2022 14:47:07 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 1AA87180E1E55 for ; Wed, 16 Feb 2022 19:47:07 +0000 (UTC) X-FDA: 79149676494.08.DA59774 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by imf26.hostedemail.com (Postfix) with ESMTP id 3F04314000A for ; Wed, 16 Feb 2022 19:47:06 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id C200FCE2889; Wed, 16 Feb 2022 19:47:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12BDDC004E1; Wed, 16 Feb 2022 19:47:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1645040821; bh=O6A+dtwhJsUxbYzeWBeyoSFV8FBZ9gZbu1DG1ZCq9zw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=WKP2MV151mFAwGNB+Ml5hTfhWp3CzXvBcrhr4CK9BGNTnXZPfzek5aGRCFU1uSfbF 80Zgb/85Ub4hd1ZTtVYGRmKa2BF8PUX2R6BOxg3h+EYCiY5vIMHUdA/OPN1hTrMmTb skZrbKhqG0Yd5WBGpUUK+J86cPggqsItAcTlUpTQ= Date: Wed, 16 Feb 2022 11:47:00 -0800 From: Andrew Morton To: Liam Howlett Cc: "maple-tree@lists.infradead.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v6 00/71] Introducing the Maple Tree Message-Id: <20220216114700.f9473d88144dc59fc4d764fb@linux-foundation.org> In-Reply-To: <20220215143728.3810954-1-Liam.Howlett@oracle.com> References: <20220215143728.3810954-1-Liam.Howlett@oracle.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=WKP2MV15; dmarc=none; spf=pass (imf26.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 3F04314000A X-Stat-Signature: zk9u57cturoqdaqm6mhu1bpchbaquk4r X-HE-Tag: 1645040826-140806 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 Tue, 15 Feb 2022 14:37:44 +0000 Liam Howlett wrote: > The maple tree is an RCU-safe range based B-tree designed to use modern > processor cache efficiently. There are a number of places in the kernel > that a non-overlapping range-based tree would be beneficial, especially > one with a simple interface. The first user that is covered in this > patch set is the vm_area_struct, where three data structures are > replaced by the maple tree: the augmented rbtree, the vma cache, and the > linked list of VMAs in the mm_struct. The long term goal is to reduce > or remove the mmap_sem contention. Has a path been chosen which gets us from here to significant reduction in mmap_lock overhead? If so, what's the plan and what must be done? Thanks.