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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 D7857C33CB2 for ; Fri, 31 Jan 2020 11:31:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A098D206F0 for ; Fri, 31 Jan 2020 11:31:44 +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="qqlgqm81" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728389AbgAaLbo (ORCPT ); Fri, 31 Jan 2020 06:31:44 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:58626 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728325AbgAaLbo (ORCPT ); Fri, 31 Jan 2020 06:31:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=KaRO3eBKc7wPtdVbBvuSCUvQxXSj5ql+XaahWnA3gzo=; b=qqlgqm81+2ljXypV4gygK9XSt lzMGytgW6z9Nw25aMB+6Ykzru03UBI14L7otvyJr8lk/rWte1zhkmlaFQqqJQEo47ynod90QWCjre 2BRn+PVmDLp9vXB27Obgz0Hspk/CLS1uO052EfYusT3pWJuUv5tJ374s90ziWzcQZvG8lU8FZw6h1 U/vKuPsm0QdVYWDWDxWvbRlcEt4D/I0t35t4RzuA8CJIZPvyhE4PPoydBDApmxzEI8CMqsqihHHGM 8WTFo2qaXOlRn5h6ldW05kaONzXwXaEaXXPSA4D6r8CTe0P98WljDkABY9sHbgWnvMm/vcSuWwYpZ 96TM659mQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1ixUWU-0003g6-Mh; Fri, 31 Jan 2020 11:31:42 +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 693B73007F2; Fri, 31 Jan 2020 12:29:55 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7253C203A5C79; Fri, 31 Jan 2020 12:31:39 +0100 (CET) Date: Fri, 31 Jan 2020 12:31:39 +0100 From: Peter Zijlstra To: Will Deacon Cc: Greg Ungerer , Geert Uytterhoeven , linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/5] Rewrite Motorola MMU page-table layout Message-ID: <20200131113139.GC14914@hirez.programming.kicks-ass.net> References: <20200129103941.304769381@infradead.org> <8a81e075-d3bd-80c1-d869-9935fdd73162@linux-m68k.org> <20200131093813.GA3938@willie-the-truck> <20200131102239.GB14914@hirez.programming.kicks-ass.net> <20200131111459.GO14946@hirez.programming.kicks-ass.net> <20200131111824.GA4298@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200131111824.GA4298@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-m68k-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.org On Fri, Jan 31, 2020 at 11:18:24AM +0000, Will Deacon wrote: > > > > +static inline pgtable_t pte_alloc_one(struct mm_struct *mm) > > > > { > > > > struct page *page = alloc_pages(GFP_DMA, 0); > > > > pte_t *pte; > Does that mean we can drop the GFP_DMA too? If so, this all ends up > looking very similar to the sun3 code wrt alloc/free and they could > probably use the same implementation (since the generic code doesn't > like out pgtable_t definition). Many software TLB archs have limits on what memory the TLB miss handler itself can access (chicken-egg issues), it might be this is where the GFP_DMA comes from. I can't quickly find this in the CFV4e docs, but I'm not really reading it carefully either.