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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 846FDC47255 for ; Fri, 8 May 2020 21:23:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5A6AC20A8B for ; Fri, 8 May 2020 21:23:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5A6AC20A8B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0B2C9900017; Fri, 8 May 2020 17:23:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 063B5900004; Fri, 8 May 2020 17:23:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EE324900017; Fri, 8 May 2020 17:23:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0117.hostedemail.com [216.40.44.117]) by kanga.kvack.org (Postfix) with ESMTP id D4950900004 for ; Fri, 8 May 2020 17:23:26 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 72EE8824805A for ; Fri, 8 May 2020 21:23:26 +0000 (UTC) X-FDA: 76794828012.15.milk55_e288e07db15 X-HE-Tag: milk55_e288e07db15 X-Filterd-Recvd-Size: 2019 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf01.hostedemail.com (Postfix) with ESMTP for ; Fri, 8 May 2020 21:23:25 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 9D471AE2A; Fri, 8 May 2020 21:23:26 +0000 (UTC) Date: Fri, 8 May 2020 23:23:21 +0200 From: Joerg Roedel To: Peter Zijlstra Cc: Joerg Roedel , x86@kernel.org, hpa@zytor.com, Dave Hansen , Andy Lutomirski , rjw@rjwysocki.net, Arnd Bergmann , Andrew Morton , Steven Rostedt , Vlastimil Babka , Michal Hocko , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH 2/7] mm/vmalloc: Track which page-table levels were modified Message-ID: <20200508212321.GR8135@suse.de> References: <20200508144043.13893-1-joro@8bytes.org> <20200508144043.13893-3-joro@8bytes.org> <20200508191048.GA2957@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200508191048.GA2957@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, May 08, 2020 at 09:10:48PM +0200, Peter Zijlstra wrote: > On Fri, May 08, 2020 at 04:40:38PM +0200, Joerg Roedel wrote: > > + if (mask & ARCH_PAGE_TABLE_SYNC_MASK) > > + arch_sync_kernel_mappings(start, end); > > So you're relying on the compiler DCE'ing the call in the 'normal' case. > > Works I suppose, but I went over the patches twice to look for a default > implementation of it before I figured that out ... Yes, works on all architectures I compile-tested this on, with gcc-9.3. I should probably add a comment about that. Joerg