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=-6.6 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 30DB9C4363D for ; Wed, 23 Sep 2020 22:47:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5DA5208E4 for ; Wed, 23 Sep 2020 22:47:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YIxI3Yt/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726787AbgIWWrU (ORCPT ); Wed, 23 Sep 2020 18:47:20 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:55836 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726199AbgIWWrU (ORCPT ); Wed, 23 Sep 2020 18:47:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600901239; h=from:from:reply-to: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=aH9LeP2g6hfwvoldu17IhkbITvXvGtTCNmXxEdiTZI4=; b=YIxI3Yt/zIcpsQEW2DMBFnVe4611iTgftbXBp5aMwo53DlUCceVy8tX1VrCt8QZVFnCxVW CMZrV27A/MBPBrr8UFwmYfTTIp4fLiojGNmk9yPflr9oNn4OvwHp5zvc1bSN2sEBcTLIAA dlREEoLqVQGqrFigW4fSDNotbVDNlGw= 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-194-XWtntuIIOsW-2ajFPIagdg-1; Wed, 23 Sep 2020 18:47:17 -0400 X-MC-Unique: XWtntuIIOsW-2ajFPIagdg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EB673100748A; Wed, 23 Sep 2020 22:47:15 +0000 (UTC) Received: from [10.64.54.94] (vpn2-54-94.bne.redhat.com [10.64.54.94]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C287978823; Wed, 23 Sep 2020 22:47:13 +0000 (UTC) Reply-To: Gavin Shan Subject: Re: [PATCH v2 0/2] arm64/mm: Enable color zero pages To: Catalin Marinas Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, anshuman.khandual@arm.com, robin.murphy@arm.com, will@kernel.org, shan.gavin@gmail.com References: <20200923053721.28873-1-gshan@redhat.com> <20200923084317.GA13434@gaia> From: Gavin Shan Message-ID: <2047fb91-da03-7774-ef5e-d194b92813c3@redhat.com> Date: Thu, 24 Sep 2020 08:47:09 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: <20200923084317.GA13434@gaia> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Catalin, On 9/23/20 6:43 PM, Catalin Marinas wrote: > On Wed, Sep 23, 2020 at 03:37:19PM +1000, Gavin Shan wrote: >> The feature of color zero pages isn't enabled on arm64, meaning all >> read-only (anonymous) VM areas are backed up by same zero page. It >> leads pressure to L1 (data) cache on reading data from them. This >> tries to enable color zero pages. >> >> PATCH[1/2] decouples the zero PGD table from zero page >> PATCH[2/2] allocates the needed zero pages according to L1 cache size > > To save you (and potential reviewers) some time, please include in the > cover letter details of a realistic workload/benchmark that is improved > by this patchset, backed by numbers. Just because it's doable and the > patches aren't too complex is not a good enough reason for merging. > Sure, Please ignore this (v2) series for now. I'll try to provide performance data in v3 even I'm not positive about that because it depends on CPU's L1 dCache size :) Cheers, Gavin