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=-3.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 7F6EBC433E0 for ; Fri, 26 Jun 2020 11:08:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55B012053B for ; Fri, 26 Jun 2020 11:08:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="RUL1JawB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728328AbgFZLIQ (ORCPT ); Fri, 26 Jun 2020 07:08:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728232AbgFZLIP (ORCPT ); Fri, 26 Jun 2020 07:08:15 -0400 Received: from casper.infradead.org (unknown [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26518C08C5C1 for ; Fri, 26 Jun 2020 04:08:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ePLLvn3g4STvMdY6WpJ5BftJMQVL6KUjzTUZoL0oc+M=; b=RUL1JawBO+l23qmfT02FPmoWAp tMzPzy2tHXhTaqOnBNg5PoGPK8XREfCJmYdDYFvM07zI8LwTH1D/O2z2q02Orb3dMyVbUDhAZeiQf l+6uG231lJ4rrYmo7LXFbc3/YiNwTnO/r2pXEmVkJKuu73pGDiyoFYBVI6qH1LKBFPIWU4y5HJado iAQWXtINr/7dHNys57uXxDXGeCqjgRMtNAHQ8qA05+a5dTbBkqpbwncx48E0nvWffbIjiacHr1Vhs 6DXBiG49zvHSYa5TSxffiERcgqTiNp6BzI8bpU0dAcJhHQvw8yIvOFSGDSg4rnJmoCCf9TyUl1sme tRaKkZ9g==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jomCi-0005mc-8q; Fri, 26 Jun 2020 11:07:34 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 7D7513007CD; Fri, 26 Jun 2020 13:07:31 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 69B8029C4228B; Fri, 26 Jun 2020 13:07:31 +0200 (CEST) Date: Fri, 26 Jun 2020 13:07:31 +0200 From: Peter Zijlstra To: Joerg Roedel Cc: x86@kernel.org, hpa@zytor.com, Dave Hansen , Andy Lutomirski , Andrew Morton , Steven Rostedt , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Joerg Roedel Subject: Re: [PATCH] x86/mm: Pre-allocate p4d/pud pages for vmalloc area Message-ID: <20200626110731.GC4817@hirez.programming.kicks-ass.net> References: <20200626093450.27741-1-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200626093450.27741-1-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 26, 2020 at 11:34:50AM +0200, Joerg Roedel wrote: > From: Joerg Roedel > > Pre-allocate the page-table pages for the vmalloc area at the level > which needs synchronization on x86. This is P4D for 5-level and PUD > for 4-level paging. > > Doing this at boot makes sure all page-tables in the system have these > pages already and do not need to be synchronized at runtime. The > runtime synchronizatin takes the pgd_lock and iterates over all > page-tables in the system, so it can take quite long and is better > avoided. > > Signed-off-by: Joerg Roedel > --- Can't we now remove arch_sync_kernel_mappings() from this same file?