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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 AE11BC46470 for ; Tue, 7 Aug 2018 08:36:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6DB572198F for ; Tue, 7 Aug 2018 08:36:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6DB572198F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733086AbeHGKtU (ORCPT ); Tue, 7 Aug 2018 06:49:20 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:57654 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726951AbeHGKtT (ORCPT ); Tue, 7 Aug 2018 06:49:19 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0570D8790A; Tue, 7 Aug 2018 08:36:04 +0000 (UTC) Received: from [10.36.116.32] (ovpn-116-32.ams2.redhat.com [10.36.116.32]) by smtp.corp.redhat.com (Postfix) with ESMTP id A59B22166BA2; Tue, 7 Aug 2018 08:36:02 +0000 (UTC) Subject: Re: [PATCH] s390x/mm: avoid taking the table lock in gmap_pmd_op_walk() To: Janosch Frank , linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org, Heiko Carstens , Martin Schwidefsky , Cornelia Huck , Christian Borntraeger References: <20180806155407.15252-1-david@redhat.com> From: David Hildenbrand Openpgp: preference=signencrypt Autocrypt: addr=david@redhat.com; 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Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 07 Aug 2018 08:36:04 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 07 Aug 2018 08:36:04 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'david@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07.08.2018 09:26, Janosch Frank wrote: > On 06.08.2018 17:54, David Hildenbrand wrote: >> Right now we temporarily take the page table lock in gmap_pmd_op_walk() >> even though we know we won't need it (if we can never have 1mb pages >> mapped into the gmap). >> >> So let's special case this, so >> gmap_protect_range()/gmap_sync_dirty_log_pmd() will not take the lock in >> case huge pages are not allowed. > > So, let's make this a special case > >> >> gmap_protect_range() is called quite frequently for managing shadow >> page tables in vSIE environments. >> >> Signed-off-by: David Hildenbrand > > If you make the patch title more specific: > Reviewed-by: Janosch Frank "s390/mm: optimize locking without huge pages in gmap_pmd_op_walk()" Thanks! -- Thanks, David / dhildenb