Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752033AbdHaVSP (ORCPT ); Thu, 31 Aug 2017 17:18:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58718 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752013AbdHaVSM (ORCPT ); Thu, 31 Aug 2017 17:18:12 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A5C1A81DEE Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=jglisse@redhat.com From: jglisse@redhat.com To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Linus Torvalds , Bernhard Held , Adam Borowski , Andrea Arcangeli , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Wanpeng Li , Paolo Bonzini , Takashi Iwai , Nadav Amit , Mike Galbraith , "Kirill A . Shutemov" , axie , Andrew Morton Subject: [PATCH 13/13] mm/mmu_notifier: kill invalidate_page Date: Thu, 31 Aug 2017 17:17:38 -0400 Message-Id: <20170831211738.17922-14-jglisse@redhat.com> In-Reply-To: <20170831211738.17922-1-jglisse@redhat.com> References: <20170831211738.17922-1-jglisse@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Thu, 31 Aug 2017 21:18:12 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4769 Lines: 128 From: Jérôme Glisse The invalidate_page callback suffered from 2 pitfalls. First it use to happen after page table lock was release and thus a new page might have setup before the call to invalidate_page() happened. This is in a weird way fix by c7ab0d2fdc840266b39db94538f74207ec2afbf6 that moved the callback under the page table lock but this also break several existing user of the mmu_notifier API that assumed they could sleep inside this callback. The second pitfall was invalidate_page being the only callback not taking a range of address in respect to invalidation but was giving an address and a page. Lot of the callback implementer assumed this could never be THP and thus failed to invalidate the appropriate range for THP. By killing this callback we unify the mmu_notifier callback API to always take a virtual address range as input. Finaly this also simplify the end user life as there is now 2 clear choice: - invalidate_range_start()/end() callback (which allow you to sleep) - invalidate_range() where you can not sleep but happen right after page table update under page table lock Signed-off-by: Jérôme Glisse Cc: Linus Torvalds Cc: Bernhard Held Cc: Adam Borowski Cc: Andrea Arcangeli Cc: Radim Krčmář Cc: Wanpeng Li Cc: Paolo Bonzini Cc: Takashi Iwai Cc: Nadav Amit Cc: Mike Galbraith Cc: Kirill A. Shutemov Cc: axie Cc: Andrew Morton --- include/linux/mmu_notifier.h | 25 ------------------------- mm/mmu_notifier.c | 14 -------------- 2 files changed, 39 deletions(-) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index c91b3bcd158f..7b2e31b1745a 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -95,17 +95,6 @@ struct mmu_notifier_ops { pte_t pte); /* - * Before this is invoked any secondary MMU is still ok to - * read/write to the page previously pointed to by the Linux - * pte because the page hasn't been freed yet and it won't be - * freed until this returns. If required set_page_dirty has to - * be called internally to this method. - */ - void (*invalidate_page)(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long address); - - /* * invalidate_range_start() and invalidate_range_end() must be * paired and are called only when the mmap_sem and/or the * locks protecting the reverse maps are held. If the subsystem @@ -220,8 +209,6 @@ extern int __mmu_notifier_test_young(struct mm_struct *mm, unsigned long address); extern void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address, pte_t pte); -extern void __mmu_notifier_invalidate_page(struct mm_struct *mm, - unsigned long address); extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm, unsigned long start, unsigned long end); extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, @@ -268,13 +255,6 @@ static inline void mmu_notifier_change_pte(struct mm_struct *mm, __mmu_notifier_change_pte(mm, address, pte); } -static inline void mmu_notifier_invalidate_page(struct mm_struct *mm, - unsigned long address) -{ - if (mm_has_notifiers(mm)) - __mmu_notifier_invalidate_page(mm, address); -} - static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm, unsigned long start, unsigned long end) { @@ -442,11 +422,6 @@ static inline void mmu_notifier_change_pte(struct mm_struct *mm, { } -static inline void mmu_notifier_invalidate_page(struct mm_struct *mm, - unsigned long address) -{ -} - static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm, unsigned long start, unsigned long end) { diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 54ca54562928..314285284e6e 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -174,20 +174,6 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address, srcu_read_unlock(&srcu, id); } -void __mmu_notifier_invalidate_page(struct mm_struct *mm, - unsigned long address) -{ - struct mmu_notifier *mn; - int id; - - id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { - if (mn->ops->invalidate_page) - mn->ops->invalidate_page(mn, mm, address); - } - srcu_read_unlock(&srcu, id); -} - void __mmu_notifier_invalidate_range_start(struct mm_struct *mm, unsigned long start, unsigned long end) { -- 2.13.5