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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 DCDC3C432C0 for ; Sun, 1 Dec 2019 01:51:09 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 941712073C for ; Sun, 1 Dec 2019 01:51:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="q8e4UkqV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 941712073C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 473636B02A0; Sat, 30 Nov 2019 20:51:09 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4250B6B02A2; Sat, 30 Nov 2019 20:51:09 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 33A066B02A3; Sat, 30 Nov 2019 20:51:09 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0018.hostedemail.com [216.40.44.18]) by kanga.kvack.org (Postfix) with ESMTP id 1D2236B02A0 for ; Sat, 30 Nov 2019 20:51:09 -0500 (EST) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id C9331180AD817 for ; Sun, 1 Dec 2019 01:51:08 +0000 (UTC) X-FDA: 76214894616.19.magic00_9f3cffaf8827 X-HE-Tag: magic00_9f3cffaf8827 X-Filterd-Recvd-Size: 5553 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf09.hostedemail.com (Postfix) with ESMTP for ; Sun, 1 Dec 2019 01:51:08 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2A418206F0; Sun, 1 Dec 2019 01:51:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575165067; bh=so4E6KVNKsv4vHKf6ha+T7+bLs2yXVSwPa1w4H0AdtY=; h=Date:From:To:Subject:From; b=q8e4UkqV3LQpAIAXnwQ25dNPa5Jo5mtcizzmCqOx3EEoZZeNAPSGenFU448lg8PM1 2YNq8RffUy3I3KYVl2fMxSSysR0TRezkWlTDlzSqUl+6C3TPPrkqUYND9RaxONUs0i mIrjcwmL8Gww9XtCIjJCjfZtJkY8t+Hy4p/YkHYs= Date: Sat, 30 Nov 2019 17:51:06 -0800 From: akpm@linux-foundation.org To: akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, arnd@arndb.de, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, npiggin@gmail.com, peterz@infradead.org, torvalds@linux-foundation.org, vgupta@synopsys.com, Vineet.Gupta1@synopsys.com, will@kernel.org Subject: [patch 037/158] ARC: mm: remove __ARCH_USE_5LEVEL_HACK Message-ID: <20191201015106.CD4zNxmtL%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: Vineet Gupta Subject: ARC: mm: remove __ARCH_USE_5LEVEL_HACK Patch series "elide extraneous generated code for folded p4d/pud/pmd", v3. This series came out of seemingly benign excursion into understanding/removing __ARCH_USE_5LEVEL_HACK from ARC port showing some extraneous code being generated despite folded p4d/pud/pmd | bloat-o-meter2 vmlinux-[AB]* | add/remove: 0/0 grow/shrink: 3/0 up/down: 130/0 (130) | function old new delta | free_pgd_range 548 660 +112 | p4d_clear_bad 2 20 +18 The patches here address that | bloat-o-meter2 vmlinux-[BF]* | add/remove: 0/2 grow/shrink: 0/1 up/down: 0/-386 (-386) | function old new delta | pud_clear_bad 20 - -20 | p4d_clear_bad 20 - -20 | free_pgd_range 660 314 -346 The code savings are not a whole lot, but still worthwhile IMHO. This patch (of 5): With paging code made 5-level compliant, this is no longer needed. ARC has software page walker with 2 lookup levels (pgd -> pte) This was expected to be non functional change but ended with slight code bloat due to needless inclusions of p*d_free_tlb() macros which will be addressed in further patches. | bloat-o-meter2 vmlinux-[AB]* | add/remove: 0/0 grow/shrink: 2/0 up/down: 128/0 (128) | function old new delta | free_pgd_range 546 656 +110 | p4d_clear_bad 2 20 +18 | Total: Before=4137148, After=4137276, chg 0.000000% Link: http://lkml.kernel.org/r/20191016162400.14796-2-vgupta@synopsys.com Signed-off-by: Vineet Gupta Acked-by: Kirill A. Shutemov Cc: "Aneesh Kumar K . V" Cc: Arnd Bergmann Cc: Linus Torvalds Cc: Nick Piggin Cc: Peter Zijlstra Cc: Will Deacon Signed-off-by: Andrew Morton --- arch/arc/include/asm/pgtable.h | 1 - arch/arc/mm/fault.c | 10 ++++++++-- arch/arc/mm/highmem.c | 4 +++- 3 files changed, 11 insertions(+), 4 deletions(-) --- a/arch/arc/include/asm/pgtable.h~arc-mm-remove-__arch_use_5level_hack +++ a/arch/arc/include/asm/pgtable.h @@ -33,7 +33,6 @@ #define _ASM_ARC_PGTABLE_H #include -#define __ARCH_USE_5LEVEL_HACK #include #include #include /* to propagate CONFIG_ARC_MMU_VER */ --- a/arch/arc/mm/fault.c~arc-mm-remove-__arch_use_5level_hack +++ a/arch/arc/mm/fault.c @@ -30,6 +30,7 @@ noinline static int handle_kernel_vaddr_ * with the 'reference' page table. */ pgd_t *pgd, *pgd_k; + p4d_t *p4d, *p4d_k; pud_t *pud, *pud_k; pmd_t *pmd, *pmd_k; @@ -39,8 +40,13 @@ noinline static int handle_kernel_vaddr_ if (!pgd_present(*pgd_k)) goto bad_area; - pud = pud_offset(pgd, address); - pud_k = pud_offset(pgd_k, address); + p4d = p4d_offset(pgd, address); + p4d_k = p4d_offset(pgd_k, address); + if (!p4d_present(*p4d_k)) + goto bad_area; + + pud = pud_offset(p4d, address); + pud_k = pud_offset(p4d_k, address); if (!pud_present(*pud_k)) goto bad_area; --- a/arch/arc/mm/highmem.c~arc-mm-remove-__arch_use_5level_hack +++ a/arch/arc/mm/highmem.c @@ -111,12 +111,14 @@ EXPORT_SYMBOL(__kunmap_atomic); static noinline pte_t * __init alloc_kmap_pgtable(unsigned long kvaddr) { pgd_t *pgd_k; + p4d_t *p4d_k; pud_t *pud_k; pmd_t *pmd_k; pte_t *pte_k; pgd_k = pgd_offset_k(kvaddr); - pud_k = pud_offset(pgd_k, kvaddr); + p4d_k = p4d_offset(pgd_k, kvaddr); + pud_k = pud_offset(p4d_k, kvaddr); pmd_k = pmd_offset(pud_k, kvaddr); pte_k = (pte_t *)memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); _