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 X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14B58C33CA1 for ; Mon, 20 Jan 2020 09:15:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D0F2820684 for ; Mon, 20 Jan 2020 09:15:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TGbrBxMl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726775AbgATJPm (ORCPT ); Mon, 20 Jan 2020 04:15:42 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:56735 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725872AbgATJPm (ORCPT ); Mon, 20 Jan 2020 04:15:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579511740; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=wCoD90tXfleo2QVgo0b+j5VFuj0bFuIVrZNZme3ikmU=; b=TGbrBxMltJpGp/beq2B3cVQMAruIRafOO4niAxHsOKXGXr0Vqdlpe3rJ2dMZ/dNneE7jx2 q/Bk7aW9Dlj2gEvzQot9qcLBC0LrEnieNXFkK3NmYQZIR/XsM1VYE3OeFu6UXiaLBGIloj nWxnDydyfqyIKbFrg0O8QcH/jf5luuw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-368-JNA-XHQxPh2meh4Qzc1Diw-1; Mon, 20 Jan 2020 04:15:37 -0500 X-MC-Unique: JNA-XHQxPh2meh4Qzc1Diw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D1129800D4E; Mon, 20 Jan 2020 09:15:35 +0000 (UTC) Received: from [10.36.118.34] (unknown [10.36.118.34]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9B4C860C18; Mon, 20 Jan 2020 09:15:33 +0000 (UTC) Subject: Re: [PATCH v4] drivers/base/memory.c: cache blocks in radix tree to accelerate lookup To: Michal Hocko , Scott Cheloha Cc: linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Greg Kroah-Hartman , Andrew Morton , nathanl@linux.ibm.com, ricklind@linux.vnet.ibm.com, Scott Cheloha , Donald Dutile References: <20191217193238-1-cheloha@linux.vnet.ibm.com> <20200109212516.17849-1-cheloha@linux.vnet.ibm.com> <181caae3-ffb8-c745-a4c9-1aef93ea6dd5@redhat.com> <20200116152214.GX19428@dhcp22.suse.cz> <765a07fe-47e9-fe3d-716a-44d9ee4a5e99@redhat.com> <20200117093514.GO19428@dhcp22.suse.cz> From: David Hildenbrand Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= mQINBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABtCREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT6JAlgEEwEIAEICGwMFCQlmAYAGCwkIBwMCBhUI AgkKCwQWAgMBAh4BAheAFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl3pImkCGQEACgkQTd4Q 9wD/g1o+VA//SFvIHUAvul05u6wKv/pIR6aICPdpF9EIgEU448g+7FfDgQwcEny1pbEzAmiw zAXIQ9H0NZh96lcq+yDLtONnXk/bEYWHHUA014A1wqcYNRY8RvY1+eVHb0uu0KYQoXkzvu+s Dncuguk470XPnscL27hs8PgOP6QjG4jt75K2LfZ0eAqTOUCZTJxA8A7E9+XTYuU0hs7QVrWJ jQdFxQbRMrYz7uP8KmTK9/Cnvqehgl4EzyRaZppshruKMeyheBgvgJd5On1wWq4ZUV5PFM4x II3QbD3EJfWbaJMR55jI9dMFa+vK7MFz3rhWOkEx/QR959lfdRSTXdxs8V3zDvChcmRVGN8U Vo93d1YNtWnA9w6oCW1dnDZ4kgQZZSBIjp6iHcA08apzh7DPi08jL7M9UQByeYGr8KuR4i6e RZI6xhlZerUScVzn35ONwOC91VdYiQgjemiVLq1WDDZ3B7DIzUZ4RQTOaIWdtXBWb8zWakt/ ztGhsx0e39Gvt3391O1PgcA7ilhvqrBPemJrlb9xSPPRbaNAW39P8ws/UJnzSJqnHMVxbRZC Am4add/SM+OCP0w3xYss1jy9T+XdZa0lhUvJfLy7tNcjVG/sxkBXOaSC24MFPuwnoC9WvCVQ ZBxouph3kqc4Dt5X1EeXVLeba+466P1fe1rC8MbcwDkoUo65Ag0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAGJAiUEGAECAA8FAlXLn5ECGwwFCQlmAYAACgkQTd4Q 9wD/g1qA6w/+M+ggFv+JdVsz5+ZIc6MSyGUozASX+bmIuPeIecc9UsFRatc91LuJCKMkD9Uv GOcWSeFpLrSGRQ1Z7EMzFVU//qVs6uzhsNk0RYMyS0B6oloW3FpyQ+zOVylFWQCzoyyf227y GW8HnXunJSC+4PtlL2AY4yZjAVAPLK2l6mhgClVXTQ/S7cBoTQKP+jvVJOoYkpnFxWE9pn4t H5QIFk7Ip8TKr5k3fXVWk4lnUi9MTF/5L/mWqdyIO1s7cjharQCstfWCzWrVeVctpVoDfJWp 4LwTuQ5yEM2KcPeElLg5fR7WB2zH97oI6/Ko2DlovmfQqXh9xWozQt0iGy5tWzh6I0JrlcxJ ileZWLccC4XKD1037Hy2FLAjzfoWgwBLA6ULu0exOOdIa58H4PsXtkFPrUF980EEibUp0zFz GotRVekFAceUaRvAj7dh76cToeZkfsjAvBVb4COXuhgX6N4pofgNkW2AtgYu1nUsPAo+NftU CxrhjHtLn4QEBpkbErnXQyMjHpIatlYGutVMS91XTQXYydCh5crMPs7hYVsvnmGHIaB9ZMfB njnuI31KBiLUks+paRkHQlFcgS2N3gkRBzH7xSZ+t7Re3jvXdXEzKBbQ+dC3lpJB0wPnyMcX FOTT3aZT7IgePkt5iC/BKBk3hqKteTnJFeVIT7EC+a6YUFg= Organization: Red Hat GmbH Message-ID: <2df18523-e410-bcfb-478e-6a7579608196@redhat.com> Date: Mon, 20 Jan 2020 10:15:32 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: <20200117093514.GO19428@dhcp22.suse.cz> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17.01.20 10:35, Michal Hocko wrote: > On Thu 16-01-20 17:17:54, David Hildenbrand wrote: > [...] >> diff --git a/drivers/base/memory.c b/drivers/base/memory.c >> index c6d288fad493..c75dec35de43 100644 >> --- a/drivers/base/memory.c >> +++ b/drivers/base/memory.c >> @@ -19,7 +19,7 @@ >> #include >> #include >> #include >> -#include >> +#include >> #include >> #include >> >> @@ -58,11 +58,11 @@ static struct bus_type memory_subsys = { >> }; >> >> /* >> - * Memory blocks are cached in a local radix tree to avoid >> + * Memory blocks are cached in a local xarray to avoid >> * a costly linear search for the corresponding device on >> * the subsystem bus. >> */ >> -static RADIX_TREE(memory_blocks, GFP_KERNEL); >> +static DEFINE_XARRAY(memory_blocks); >> >> static BLOCKING_NOTIFIER_HEAD(memory_chain); >> >> @@ -566,7 +566,7 @@ static struct memory_block *find_memory_block_by_id(unsigned long block_id) >> { >> struct memory_block *mem; >> >> - mem = radix_tree_lookup(&memory_blocks, block_id); >> + mem = xa_load(&memory_blocks, block_id); >> if (mem) >> get_device(&mem->dev); >> return mem; >> @@ -621,7 +621,8 @@ int register_memory(struct memory_block *memory) >> put_device(&memory->dev); >> return ret; >> } >> - ret = radix_tree_insert(&memory_blocks, memory->dev.id, memory); >> + ret = xa_err(xa_store(&memory_blocks, memory->dev.id, memory, >> + GFP_KERNEL)); >> if (ret) { >> put_device(&memory->dev); >> device_unregister(&memory->dev); >> @@ -683,7 +684,7 @@ static void unregister_memory(struct memory_block *memory) >> if (WARN_ON_ONCE(memory->dev.bus != &memory_subsys)) >> return; >> >> - WARN_ON(radix_tree_delete(&memory_blocks, memory->dev.id) == NULL); >> + WARN_ON(xa_erase(&memory_blocks, memory->dev.id) == NULL); >> >> /* drop the ref. we got via find_memory_block() */ >> put_device(&memory->dev); > > OK, this looks sensible. xa_store shouldn't ever return an existing > device as we do the lookpup beforehand so good. We might need to > reorganize the code if we want to drop the loopup though. Ping Scott. Will you resend a cleanup like this as a proper patch or shall I? -- Thanks, David / dhildenb