From patchwork Thu Aug 30 16:15:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 145541 Delivered-To: patch@linaro.org Received: by 2002:a2e:1648:0:0:0:0:0 with SMTP id 8-v6csp91507ljw; Thu, 30 Aug 2018 09:15:54 -0700 (PDT) X-Google-Smtp-Source: ANB0Vda+OAKxnsWT5mqFsfJ4bJ2KJR7so0Vps96H470Okypx9/p3Y+/VvIJLnVp6C3gMv8QIe43c X-Received: by 2002:a63:25c4:: with SMTP id l187-v6mr2927393pgl.29.1535645754025; Thu, 30 Aug 2018 09:15:54 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1535645754; cv=none; d=google.com; s=arc-20160816; b=GrNzFqJwSKT4s0J+mSJIviifnwrqjbolbfjiTidVOY6EbajbXoBB21UaawTMPDqbOm yWZCLWsgXo6BYP8wgFqRJhjssaK7ZYnpejSnxZYtlwVZJw0QKuf+x1BtwgxXx7DdSXXD oUKJ/BW2xxKsHzN2tAQqQLDBdsLwt490z7DDOaDdjjO3HWldlNsvIjUITIReSU7yykD9 V8vTGzZR3Yr4wEyYeBM5mKdWjGH8eNGqPJ32mPHSDeliRC/kGi6R0tXu3ODQWWuft8zq JPujRRTRQKuyLoQ+9GO6R/0jRbk9rmRr59iJMKGcRg8rLVMipUrhEJIxy+UaDtkYdDJm ylCg== 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=nKTh2h87IGhzz0IU3ONqDl5lCe5G3nOhnEHhJ2K5Hic=; b=a3Qb4zkWf0pRsAR/a2mNdbfwcYIo2XcZ7r799RR7B38vdeyett+JrN3gyMh1V2sQ21 7QakkvnOL4tGl6W06GsmvC70h5rXAW9rxYgBxtQ3hD2MrmK8YPInVFoabzVVMm/NKfat 2zqJzCBO5ZagOm4UM8ronWgI/V0/und0MR6Su08ESMGWKak5W8SkyVlMLfvBZaRVSXrY PtwCy/zcoSqlIEhY4x3Jj8HlpU9e/6omzUFPd1h4hW5wnOlP5UBTrZrfXqiCr1auso0D 2gIdJRrQ00awxuB4ZRD8twdM4vyFuDEnzeoMhtiX2w3Aj0tO/5gIJzyJxPKi0YAe/SYz TE0Q== 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 s12-v6si6985382plr.120.2018.08.30.09.15.53; Thu, 30 Aug 2018 09:15:54 -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 S1727746AbeH3USo (ORCPT + 32 others); Thu, 30 Aug 2018 16:18:44 -0400 Received: from foss.arm.com ([217.140.101.70]:44884 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727614AbeH3USn (ORCPT ); Thu, 30 Aug 2018 16:18:43 -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 1016C1B4B; Thu, 30 Aug 2018 09:15:50 -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 D49E13F93D; Thu, 30 Aug 2018 09:15:49 -0700 (PDT) Received: by edgewater-inn.cambridge.arm.com (Postfix, from userid 1000) id A1FE41AE3A7A; Thu, 30 Aug 2018 17:16:01 +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: [PATCH 09/12] asm-generic/tlb: Track which levels of the page tables have been cleared Date: Thu, 30 Aug 2018 17:15:43 +0100 Message-Id: <1535645747-9823-10-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1535645747-9823-1-git-send-email-will.deacon@arm.com> References: <1535645747-9823-1-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 | 58 ++++++++++++++++++++++++++++++++++++++++------- mm/memory.c | 4 +++- 2 files changed, 53 insertions(+), 9 deletions(-) -- 2.1.4 Acked-by: Nicholas Piggin diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 2b444ad94566..9791e98122a0 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 +211,25 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, } #endif +static inline unsigned long tlb_get_unmap_shift(struct mmu_gather *tlb) +{ + if (tlb->cleared_ptes) + return PAGE_SHIFT; + if (tlb->cleared_pmds) + return PMD_SHIFT; + if (tlb->cleared_puds) + return PUD_SHIFT; + if (tlb->cleared_p4ds) + return P4D_SHIFT; + + return PAGE_SHIFT; +} + +static inline unsigned long tlb_get_unmap_size(struct mmu_gather *tlb) +{ + return 1UL << tlb_get_unmap_shift(tlb); +} + /* * 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 +263,19 @@ 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 +289,7 @@ 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 +304,7 @@ 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 +330,8 @@ 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 +340,8 @@ 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 +351,8 @@ 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 +363,7 @@ 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 c467102a5cbc..9135f48e8d84 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);