From patchwork Fri Aug 24 15:52:44 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 145077 Delivered-To: patch@linaro.org Received: by 2002:a2e:1648:0:0:0:0:0 with SMTP id 8-v6csp1410627ljw; Fri, 24 Aug 2018 08:53:00 -0700 (PDT) X-Google-Smtp-Source: ANB0VdZweJJYqxDR+y/n6/hEsvDauWPZYWcs0K2U3sXyPOpkSFWn5XONVrBpLo4I38c0iqvKw6k7 X-Received: by 2002:a62:83ca:: with SMTP id h193-v6mr2588133pfe.123.1535125980209; Fri, 24 Aug 2018 08:53:00 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1535125980; cv=none; d=google.com; s=arc-20160816; b=N24fQ4DQ0Q5L9Jnx4gMKtOCAtid4CJZrqwgKp1xTpp1f7rTV3hAUCyl7UHWMwwZzBv vGZolQgwgn1iXFe/iocooMAezVCYQ+xaHORAu6H0wix1NOW7pVYfHH33hSHSu1lf0GBB U+llSmrDxEc+/rut72lnuHTr02RxKxAx8Da9E4qqP7THxM7Z4uGJQXTf2KSy/YQPQibD I38pn8F4iA4TYyaeayc2ZO/hxccFwkRe99jPGiwxh2QQzFnLsYa9feJy9waLqQx3FW33 UMbY1VXhsJ/GhqNMcK3b8WjzA5K03zvxrULi0YTDN2Gp+a80GJgEdYAHIyrLYCPWxedp tZZw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=dk/EKGepgL0z5A9hRjkk9ipN1K0IzqwFKPaRUTcQyic=; b=j/cM2JEXXoks1uVyw1f1uWRO2Rx5UN/gSRZjn4do9mTsXt/2hnQ4Hzagos82gL0IXD 0daNn4dE/wkpx2EbcdmAIJzFZuuyGHenNt/+5hokZiP8TmfNDBJPEkmozz8NDya9K7Qg fGJ+gqP65KdVNwt18ePNP6HEmw4hFAph+IsShbFJxTYXCTVazoC+Z0kMB8nnIQx5JZfj zeuPfnzfY4EjVTeEKhJ9D/XsOu+/Gp3cpNsw1G2dOAhAmmtJAQ4BtRZA1/8ZwNiG5nJl yFkWftMbzkd+Wl6hJamLBmuRlNstQ4/sFtgaImA64hWpC7JygiDjsCdsXooc+lcWTkHB WUcQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id r206-v6si7404272pgr.17.2018.08.24.08.52.59; Fri, 24 Aug 2018 08:53:00 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728048AbeHXT2L (ORCPT + 32 others); Fri, 24 Aug 2018 15:28:11 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:32890 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727597AbeHXT1w (ORCPT ); Fri, 24 Aug 2018 15:27:52 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DFFD91A25; Fri, 24 Aug 2018 08:52:38 -0700 (PDT) Received: from edgewater-inn.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B28103F93D; Fri, 24 Aug 2018 08:52:38 -0700 (PDT) Received: by edgewater-inn.cambridge.arm.com (Postfix, from userid 1000) id 3E84B1AE33CF; Fri, 24 Aug 2018 16:52:48 +0100 (BST) From: Will Deacon To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, benh@au1.ibm.com, torvalds@linux-foundation.org, npiggin@gmail.com, catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, Will Deacon Subject: [RFC PATCH 09/11] asm-generic/tlb: Track which levels of the page tables have been cleared Date: Fri, 24 Aug 2018 16:52:44 +0100 Message-Id: <1535125966-7666-10-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1535125966-7666-1-git-send-email-will.deacon@arm.com> References: <1535125966-7666-1-git-send-email-will.deacon@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is common for architectures with hugepage support to require only a single TLB invalidation operation per hugepage during unmap(), rather than iterating through the mapping at a PAGE_SIZE increment. Currently, however, the level in the page table where the unmap() operation occurs is not stored in the mmu_gather structure, therefore forcing architectures to issue additional TLB invalidation operations or to give up and over-invalidate by e.g. invalidating the entire TLB. Ideally, we could add an interval rbtree to the mmu_gather structure, which would allow us to associate the correct mapping granule with the various sub-mappings within the range being invalidated. However, this is costly in terms of book-keeping and memory management, so instead we approximate by keeping track of the page table levels that are cleared and provide a means to query the smallest granule required for invalidation. Signed-off-by: Will Deacon --- include/asm-generic/tlb.h | 53 ++++++++++++++++++++++++++++++++++++++++------- mm/memory.c | 4 +++- 2 files changed, 48 insertions(+), 9 deletions(-) -- 2.1.4 diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index a5caf90264e6..081b105d7215 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -116,6 +116,14 @@ struct mmu_gather { */ unsigned int freed_tables : 1; + /* + * at which levels have we cleared entries? + */ + unsigned int cleared_ptes : 1; + unsigned int cleared_pmds : 1; + unsigned int cleared_puds : 1; + unsigned int cleared_p4ds : 1; + struct mmu_gather_batch *active; struct mmu_gather_batch local; struct page *__pages[MMU_GATHER_BUNDLE]; @@ -150,6 +158,10 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb) tlb->end = 0; } tlb->freed_tables = 0; + tlb->cleared_ptes = 0; + tlb->cleared_pmds = 0; + tlb->cleared_puds = 0; + tlb->cleared_p4ds = 0; } static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) @@ -199,6 +211,20 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, } #endif +static inline unsigned long tlb_get_unmap_granule(struct mmu_gather *tlb) +{ + if (tlb->cleared_ptes) + return PAGE_SIZE; + if (tlb->cleared_pmds) + return PMD_SIZE; + if (tlb->cleared_puds) + return PUD_SIZE; + if (tlb->cleared_p4ds) + return P4D_SIZE; + + return PAGE_SIZE; +} + /* * In the case of tlb vma handling, we can optimise these away in the * case where we're doing a full MM flush. When we're doing a munmap, @@ -232,13 +258,19 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, #define tlb_remove_tlb_entry(tlb, ptep, address) \ do { \ __tlb_adjust_range(tlb, address, PAGE_SIZE); \ + tlb->cleared_ptes = 1; \ __tlb_remove_tlb_entry(tlb, ptep, address); \ } while (0) -#define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \ - do { \ - __tlb_adjust_range(tlb, address, huge_page_size(h)); \ - __tlb_remove_tlb_entry(tlb, ptep, address); \ +#define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \ + do { \ + unsigned long _sz = huge_page_size(h); \ + __tlb_adjust_range(tlb, address, _sz); \ + if (_sz == PMD_SIZE) \ + tlb->cleared_pmds = 1; \ + else if (_sz == PUD_SIZE) \ + tlb->cleared_puds = 1; \ + __tlb_remove_tlb_entry(tlb, ptep, address); \ } while (0) /** @@ -252,6 +284,7 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, #define tlb_remove_pmd_tlb_entry(tlb, pmdp, address) \ do { \ __tlb_adjust_range(tlb, address, HPAGE_PMD_SIZE); \ + tlb->cleared_pmds = 1; \ __tlb_remove_pmd_tlb_entry(tlb, pmdp, address); \ } while (0) @@ -266,6 +299,7 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, #define tlb_remove_pud_tlb_entry(tlb, pudp, address) \ do { \ __tlb_adjust_range(tlb, address, HPAGE_PUD_SIZE); \ + tlb->cleared_puds = 1; \ __tlb_remove_pud_tlb_entry(tlb, pudp, address); \ } while (0) @@ -291,7 +325,8 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, #define pte_free_tlb(tlb, ptep, address) \ do { \ __tlb_adjust_range(tlb, address, PAGE_SIZE); \ - tlb->freed_tables = 1; \ + tlb->freed_tables = 1; \ + tlb->cleared_pmds = 1; \ __pte_free_tlb(tlb, ptep, address); \ } while (0) #endif @@ -300,7 +335,8 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, #define pmd_free_tlb(tlb, pmdp, address) \ do { \ __tlb_adjust_range(tlb, address, PAGE_SIZE); \ - tlb->freed_tables = 1; \ + tlb->freed_tables = 1; \ + tlb->cleared_puds = 1; \ __pmd_free_tlb(tlb, pmdp, address); \ } while (0) #endif @@ -310,7 +346,8 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, #define pud_free_tlb(tlb, pudp, address) \ do { \ __tlb_adjust_range(tlb, address, PAGE_SIZE); \ - tlb->freed_tables = 1; \ + tlb->freed_tables = 1; \ + tlb->cleared_p4ds = 1; \ __pud_free_tlb(tlb, pudp, address); \ } while (0) #endif @@ -321,7 +358,7 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, #define p4d_free_tlb(tlb, pudp, address) \ do { \ __tlb_adjust_range(tlb, address, PAGE_SIZE); \ - tlb->freed_tables = 1; \ + tlb->freed_tables = 1; \ __p4d_free_tlb(tlb, pudp, address); \ } while (0) #endif diff --git a/mm/memory.c b/mm/memory.c index 83aef222f11b..69982d1d9b7a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -267,8 +267,10 @@ void arch_tlb_finish_mmu(struct mmu_gather *tlb, { struct mmu_gather_batch *batch, *next; - if (force) + if (force) { + __tlb_reset_range(tlb); __tlb_adjust_range(tlb, start, end - start); + } tlb_flush_mmu(tlb);