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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9875FC67871 for ; Mon, 24 Oct 2022 20:43:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234030AbiJXUnZ (ORCPT ); Mon, 24 Oct 2022 16:43:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234940AbiJXUmq (ORCPT ); Mon, 24 Oct 2022 16:42:46 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C6FB2A725 for ; Mon, 24 Oct 2022 11:51:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666637425; 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; bh=6tuQ1z80Jxwl1KqjcwzqroneyxDi+hcFmfKt3WRAZA0=; b=ZxV9pQ/9+e2tTz+/AN1bQrVFim8A24DCrFwl+WtNM9PzLzaE690jHC7Lmht03QTgFX9GgG a7bqX71gppTaXy5/nqlPzYXbxuQZK6D9DFSOCxf37a+tDeRfXWVj/sWv58q4O68Jqpi9HD y/D6JCcBdqbdXk9YWA+2RY0IAAYdpi4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-662-Du_a6b-eM-OZIubBtyqy8Q-1; Mon, 24 Oct 2022 14:47:08 -0400 X-MC-Unique: Du_a6b-eM-OZIubBtyqy8Q-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9FF3E88282F; Mon, 24 Oct 2022 18:47:07 +0000 (UTC) Received: from [10.18.17.153] (dhcp-17-153.bos.redhat.com [10.18.17.153]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9944F40C955E; Mon, 24 Oct 2022 18:47:05 +0000 (UTC) Message-ID: <4ac8ed1b-6f2c-5083-fae3-4b6fe9e8cf1b@redhat.com> Date: Mon, 24 Oct 2022 14:46:49 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.0 Subject: Re: [PATCH v4 3/5] locking/rwsem: Change waiter->hanodff_set to a handoff_state enum Content-Language: en-US To: john.p.donnelly@oracle.com, Peter Zijlstra , Ingo Molnar , Will Deacon , Boqun Feng Cc: linux-kernel@vger.kernel.org, Hillf Danton , Mukesh Ojha , =?UTF-8?B?VGluZzExIFdhbmcg546L5am3?= , Jack Vogel , Jorge Lopez , Vijayendra Suman References: <20221024174418.796468-1-longman@redhat.com> <20221024174418.796468-4-longman@redhat.com> From: Waiman Long In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/24/22 14:25, john.p.donnelly@oracle.com wrote: > On 10/24/22 12:44 PM, Waiman Long wrote: >> Change the boolean waiter->handoff_set to an enum type so that we can >> have more states in some later patches. Also use READ_ONCE() outside >> wait_lock critical sections for read and WRITE_ONCE() inside wait_lock >> critical sections for write for proper synchronization. There is no >> functional change. > > Hi, > > Do we need > > > Fixes: d257cc8cb8d5 ("locking/rwsem: Make handoff bit handling more > consistent") > > Fixes: 91d2a812dfb9 ("locking/rwsem: Make handoff writer > optimistically spin on owner") > > Cc: stable@vger.kernel.org > > > clauses added to patches 3,4,5 so they are all picked up in one series ? > > Thank you, > > John. I am not planning to do that. The handoff code rewrite represent a moderate amount of changes. So I don't want them to be backported to stable in case there are some hidden bugs inside. That is why I have patch 2 is essentially reverted in patch 4. Cheers, Longman