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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 6E8F7C43381 for ; Tue, 26 Jan 2021 18:15:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DFFE230FC for ; Tue, 26 Jan 2021 18:15:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394373AbhAZSPg (ORCPT ); Tue, 26 Jan 2021 13:15:36 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:29487 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393816AbhAZR4y (ORCPT ); Tue, 26 Jan 2021 12:56:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611683727; 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=rMaRRif4x/o1qr3EHWx3D3A3paOWJunfGP7cUczujlk=; b=APJk68J32PY3pKhg5gMrs+7PPZIDeDLVaivQG4R9b5fIWnqz2yIfd7ev86YFqTc27vY/m+ m/7fo38AUIO5EgjCiU3aGxFLml/iB4F7ZfUg3DbpDZ43Cgii16N780VGmxkKOqP3xNNvjH B0y8sKdKnBUnIUvNgZGgwK2nViyDz9w= Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-400-qdDcLVCZMualDhxZR39wfA-1; Tue, 26 Jan 2021 12:55:25 -0500 X-MC-Unique: qdDcLVCZMualDhxZR39wfA-1 Received: by mail-ed1-f70.google.com with SMTP id m18so3126120edp.13 for ; Tue, 26 Jan 2021 09:55:24 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=rMaRRif4x/o1qr3EHWx3D3A3paOWJunfGP7cUczujlk=; b=KAIM3fhpAKsOSeJFzJJF3cv9DyG9x6TMniwgAwvE3y0izmm3VlQisZbT++JPoznLbm A6HrWIi7Gxfy0ByaciD5a6Dy4YOaFLq+7FiGBO9oBvxdH+Ah7dTZZ1WQZ+MBhOwOe+zy LOFX9nUgE4mF+GE9DoaijHxIl1KjQQ+YQ5pv/4ZFmfF9WXQCV3/BidieV0SbYgVkXLWw hfinru9v/eWS7cF7TePiiPC2AENWWr09FgWWV+7Cw4xEEogFIh6qGWej+YOpImLnpViZ pdBatrOfokzydAKKhYAlPsNEHT3MQPCnhcPrNXLqsflU4bkiliU5+gfgQc+1qRZkodjG CBCw== X-Gm-Message-State: AOAM533skGwVZ3AvKKPzFwhwbpWy70QpQZixgxr1imUcKL6o51rx/8RA qtc3j1A2HhnJ5ply+jY7MAk5kl+ayNEy32LSN60qXRyq4wPnU2bQ2E1sJr9vkdQ8a1S5eRrLdd1 K4y4kteZvaNbr3j2zu2UX0vXb X-Received: by 2002:a17:906:4159:: with SMTP id l25mr3994039ejk.311.1611683723883; Tue, 26 Jan 2021 09:55:23 -0800 (PST) X-Google-Smtp-Source: ABdhPJw6rarq4cXLZKda6ZVXoCfOJgKXeUCmPj3eahyTXTqq3OCDu6EEaLCS8azd/93eAI0Bboegcg== X-Received: by 2002:a17:906:4159:: with SMTP id l25mr3993860ejk.311.1611683718719; Tue, 26 Jan 2021 09:55:18 -0800 (PST) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id x16sm10255151ejc.22.2021.01.26.09.55.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 26 Jan 2021 09:55:17 -0800 (PST) Subject: Re: [PATCH 15/24] kvm: mmu: Wrap mmu_lock cond_resched and needbreak To: Ben Gardon Cc: Sean Christopherson , LKML , kvm , Peter Xu , Peter Shier , Peter Feiner , Junaid Shahid , Jim Mattson , Yulei Zhang , Wanpeng Li , Vitaly Kuznetsov , Xiao Guangrong References: <20210112181041.356734-1-bgardon@google.com> <20210112181041.356734-16-bgardon@google.com> <460d38b9-d920-9339-1293-5900d242db37@redhat.com> From: Paolo Bonzini Message-ID: Date: Tue, 26 Jan 2021 18:55:13 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26/01/21 18:47, Ben Gardon wrote: > Enough that it motivated me to implement this more complex union > scheme. While the difference was pronounced in the dirty log perf test > microbenchmark, it's an open question as to whether it would matter in > practice. I'll look at getting some numbers if it's just the dirty log perf test. Did you see anything in the profile pointing specifically at rwlock? Paolo