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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 77064C32767 for ; Mon, 6 Jan 2020 06:02:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A05E218AC for ; Mon, 6 Jan 2020 06:02:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578290546; bh=zI7gBUNWlwkd3lFKva8XGnIwM1FVpFdgHUCAPBjSOs4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=yx35R1+hHIz7y6bqsiIyP9OQEkOqBXsvnxanxCA/t0K11houzm2QjQ2Xc1y08X/7c TRem8FBOKpuqMP6yakwjayA65n8Mje15mMbu8/snVILTB9I/aFP2TWVvCZ/Lt9Pg/5 001eI6hlGyW55l/cswvWp0APR7s+zD+JoyUhLm14= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726789AbgAFGCZ (ORCPT ); Mon, 6 Jan 2020 01:02:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:45778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726338AbgAFGCZ (ORCPT ); Mon, 6 Jan 2020 01:02:25 -0500 Received: from rapoport-lnx (nesher1.haifa.il.ibm.com [195.110.40.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5EBE120848; Mon, 6 Jan 2020 06:02:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578290544; bh=zI7gBUNWlwkd3lFKva8XGnIwM1FVpFdgHUCAPBjSOs4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LsnFF2geI19fPlwyYS15EN2J122xcAAudU7qPjc8Yg8rj5+ulcbot7RHDI/0f0a4C CzKbNb50SqVOcIHiHpJY8bFWvC6xxVOQQiQTcEG7yINVvo5T+t1qoSg+qcErMRoY42 338+xYqXNsf3EA8fzviqqEB6MSOOfTBSjuQLpYEE= Date: Mon, 6 Jan 2020 08:02:18 +0200 From: Mike Rapoport To: Michael Ellerman Cc: Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mike Rapoport Subject: Re: [PATCH] powerpc: add support for folded p4d page tables Message-ID: <20200106060217.GA5444@rapoport-lnx> References: <20191209150908.6207-1-rppt@kernel.org> <20200102081059.GA12063@rapoport-lnx> <87v9ppi7ky.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87v9ppi7ky.fsf@mpe.ellerman.id.au> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 06, 2020 at 02:31:41PM +1100, Michael Ellerman wrote: > Mike Rapoport writes: > > Any updates on this? > > It's very ... big, and kind of intrusive. I've tried to split it to several smaller ones, but I couldn't find a way to do it without breaking bisectability. As for the intrusive, most of the changes are mechanical > It's not an improvement as far as the powerpc code's readability is > concerned. I assume the plan is that the 5-level hack can eventually be > removed and so this conversion is a prerequisite for that? Yep, the idea is to remove asm-generic/pgtable-nop4d-hack.h and asm-generic/5level-fixup.h. And, there is a small benefit for powerpc as kernel size is reduced a bit, e.g. for pseries_defconfig: $ size old/vmlinux new/vmlinux text data bss dec hex filename 13702955 5961022 1517520 21181497 1433439 old/vmlinux 13702507 5961006 1517520 21181033 1433269 new/vmlinux > cheers > > > On Mon, Dec 09, 2019 at 05:09:08PM +0200, Mike Rapoport wrote: > >> From: Mike Rapoport > >> > >> Implement primitives necessary for the 4th level folding, add walks of p4d > >> level where appropriate and replace 5level-fixup.h with pgtable-nop4d.h. > >> > >> Signed-off-by: Mike Rapoport > >> --- > >> arch/powerpc/include/asm/book3s/32/pgtable.h | 1 - > >> arch/powerpc/include/asm/book3s/64/hash.h | 4 +- > >> arch/powerpc/include/asm/book3s/64/pgalloc.h | 4 +- > >> arch/powerpc/include/asm/book3s/64/pgtable.h | 58 ++++++++++-------- > >> arch/powerpc/include/asm/book3s/64/radix.h | 6 +- > >> arch/powerpc/include/asm/nohash/32/pgtable.h | 1 - > >> arch/powerpc/include/asm/nohash/64/pgalloc.h | 2 +- > >> .../include/asm/nohash/64/pgtable-4k.h | 32 +++++----- > >> arch/powerpc/include/asm/nohash/64/pgtable.h | 6 +- > >> arch/powerpc/include/asm/pgtable.h | 8 +++ > >> arch/powerpc/kvm/book3s_64_mmu_radix.c | 59 ++++++++++++++++--- > >> arch/powerpc/lib/code-patching.c | 7 ++- > >> arch/powerpc/mm/book3s32/mmu.c | 2 +- > >> arch/powerpc/mm/book3s32/tlb.c | 4 +- > >> arch/powerpc/mm/book3s64/hash_pgtable.c | 4 +- > >> arch/powerpc/mm/book3s64/radix_pgtable.c | 19 ++++-- > >> arch/powerpc/mm/book3s64/subpage_prot.c | 6 +- > >> arch/powerpc/mm/hugetlbpage.c | 28 +++++---- > >> arch/powerpc/mm/kasan/kasan_init_32.c | 8 +-- > >> arch/powerpc/mm/mem.c | 4 +- > >> arch/powerpc/mm/nohash/40x.c | 4 +- > >> arch/powerpc/mm/nohash/book3e_pgtable.c | 15 +++-- > >> arch/powerpc/mm/pgtable.c | 25 +++++++- > >> arch/powerpc/mm/pgtable_32.c | 28 +++++---- > >> arch/powerpc/mm/pgtable_64.c | 10 ++-- > >> arch/powerpc/mm/ptdump/hashpagetable.c | 20 ++++++- > >> arch/powerpc/mm/ptdump/ptdump.c | 22 ++++++- > >> arch/powerpc/xmon/xmon.c | 17 +++++- > >> 28 files changed, 284 insertions(+), 120 deletions(-) > -- Sincerely yours, Mike.