From nobody Mon Apr 6 09:19:40 2026 Received: from out30-118.freemail.mail.aliyun.com (out30-118.freemail.mail.aliyun.com [115.124.30.118]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B541335BA7; Sat, 21 Mar 2026 06:43:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.118 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774075409; cv=none; b=IPlRyvj10eL98aUxjKge6J6htptF0lUhzxriJji4hJHbo9mJt89AVzrT1Ztd6TLcucioZMS1HGJe176cfEcqfslvButVgul6p4l3xQCiGz+hxajjxKZ6LEE+m3bpSTR8Rcd+mf9wnDVWbgBlLfhtZVk5eIRj04NGBYu3YdeZhC0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774075409; c=relaxed/simple; bh=mNo/7grXPZc8hWnvQGWsmufVobqlLfbvnfADeuIzla4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ggqxq2KpJirClkavRGYFJKeyc1/AK3c5HQeDA721oI2ouYg1ebGXMZizbtSnro5qQsJ238EQIl/ziLgUT7CXQ6Q7G4uEDeqwXnhIFYpxDakczDfHbn1w66YPT7zv2357X1tr+fvQun0SiKlSbnggkoMoQ2xuQarjrYCXjt2E9jY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=xmnOnySo; arc=none smtp.client-ip=115.124.30.118 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="xmnOnySo" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1774075396; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=TmudzNicNUiCl0daaMXprBQaBaWvZIMFkUgBsUIOa+M=; b=xmnOnySojUaXnDbRJBFQd4ROvaHwGIYlbzlYGMzP9+UOj0glPquP2TXpNcvXjXxgASVgXU2YvYaW533TdYKR9netOf0PQ/JIGZo3YI5jSX1iNGZiY9X1lK0rgU/AhydKe7b18Upg+j/nEcUuHczZVtmWo6UzKchvnENgHNM7MP8= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037009110;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0X.ODaLu_1774075394; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0X.ODaLu_1774075394 cluster:ay36) by smtp.aliyun-inc.com; Sat, 21 Mar 2026 14:43:15 +0800 From: Baolin Wang To: akpm@linux-foundation.org, david@kernel.org Cc: ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, baolin.wang@linux.alibaba.com, linux-arm-kernel@lists.infradead.org, x86@kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org (open), linux-kernel@vger.kernel.org Subject: [PATCH v2 6/6] mm: change to return bool for the MMU notifier's young flag check Date: Sat, 21 Mar 2026 14:42:54 +0800 Message-ID: X-Mailer: git-send-email 2.47.3 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The MMU notifier young flag check related functions only return whether the young flag was set. Change the return type to bool to make the intention clearer. Reviewed-by: Lorenzo Stoakes (Oracle) Signed-off-by: Baolin Wang --- include/linux/mmu_notifier.h | 76 +++++++++++++++++------------------- mm/internal.h | 16 ++++---- mm/mmu_notifier.c | 23 +++++------ virt/kvm/kvm_main.c | 31 ++++++--------- 4 files changed, 66 insertions(+), 80 deletions(-) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 3705d350c863..17f2cdc77dd5 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -97,20 +97,20 @@ struct mmu_notifier_ops { * Start-end is necessary in case the secondary MMU is mapping the page * at a smaller granularity than the primary MMU. */ - int (*clear_flush_young)(struct mmu_notifier *subscription, - struct mm_struct *mm, - unsigned long start, - unsigned long end); + bool (*clear_flush_young)(struct mmu_notifier *subscription, + struct mm_struct *mm, + unsigned long start, + unsigned long end); =20 /* * clear_young is a lightweight version of clear_flush_young. Like the * latter, it is supposed to test-and-clear the young/accessed bitflag * in the secondary pte, but it may omit flushing the secondary tlb. */ - int (*clear_young)(struct mmu_notifier *subscription, - struct mm_struct *mm, - unsigned long start, - unsigned long end); + bool (*clear_young)(struct mmu_notifier *subscription, + struct mm_struct *mm, + unsigned long start, + unsigned long end); =20 /* * test_young is called to check the young/accessed bitflag in @@ -118,9 +118,9 @@ struct mmu_notifier_ops { * frequently used without actually clearing the flag or tearing * down the secondary mapping on the page. */ - int (*test_young)(struct mmu_notifier *subscription, - struct mm_struct *mm, - unsigned long address); + bool (*test_young)(struct mmu_notifier *subscription, + struct mm_struct *mm, + unsigned long address); =20 /* * invalidate_range_start() and invalidate_range_end() must be @@ -376,14 +376,12 @@ mmu_interval_check_retry(struct mmu_interval_notifier= *interval_sub, =20 extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm); extern void __mmu_notifier_release(struct mm_struct *mm); -extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm, - unsigned long start, - unsigned long end); -extern int __mmu_notifier_clear_young(struct mm_struct *mm, - unsigned long start, - unsigned long end); -extern int __mmu_notifier_test_young(struct mm_struct *mm, - unsigned long address); +bool __mmu_notifier_clear_flush_young(struct mm_struct *mm, + unsigned long start, unsigned long end); +bool __mmu_notifier_clear_young(struct mm_struct *mm, + unsigned long start, unsigned long end); +bool __mmu_notifier_test_young(struct mm_struct *mm, + unsigned long address); extern int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range= *r); extern void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range = *r); extern void __mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct= *mm, @@ -403,30 +401,28 @@ static inline void mmu_notifier_release(struct mm_str= uct *mm) __mmu_notifier_release(mm); } =20 -static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm, - unsigned long start, - unsigned long end) +static inline bool mmu_notifier_clear_flush_young(struct mm_struct *mm, + unsigned long start, unsigned long end) { if (mm_has_notifiers(mm)) return __mmu_notifier_clear_flush_young(mm, start, end); - return 0; + return false; } =20 -static inline int mmu_notifier_clear_young(struct mm_struct *mm, - unsigned long start, - unsigned long end) +static inline bool mmu_notifier_clear_young(struct mm_struct *mm, + unsigned long start, unsigned long end) { if (mm_has_notifiers(mm)) return __mmu_notifier_clear_young(mm, start, end); - return 0; + return false; } =20 -static inline int mmu_notifier_test_young(struct mm_struct *mm, - unsigned long address) +static inline bool mmu_notifier_test_young(struct mm_struct *mm, + unsigned long address) { if (mm_has_notifiers(mm)) return __mmu_notifier_test_young(mm, address); - return 0; + return false; } =20 static inline void @@ -552,24 +548,22 @@ static inline void mmu_notifier_release(struct mm_str= uct *mm) { } =20 -static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm, - unsigned long start, - unsigned long end) +static inline bool mmu_notifier_clear_flush_young(struct mm_struct *mm, + unsigned long start, unsigned long end) { - return 0; + return false; } =20 -static inline int mmu_notifier_clear_young(struct mm_struct *mm, - unsigned long start, - unsigned long end) +static inline bool mmu_notifier_clear_young(struct mm_struct *mm, + unsigned long start, unsigned long end) { - return 0; + return false; } =20 -static inline int mmu_notifier_test_young(struct mm_struct *mm, - unsigned long address) +static inline bool mmu_notifier_test_young(struct mm_struct *mm, + unsigned long address) { - return 0; + return false; } =20 static inline void diff --git a/mm/internal.h b/mm/internal.h index 0eaca2f0eb6a..3d6eba216364 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1831,10 +1831,10 @@ static inline int io_remap_pfn_range_complete(struc= t vm_area_struct *vma, } =20 #ifdef CONFIG_MMU_NOTIFIER -static inline int clear_flush_young_ptes_notify(struct vm_area_struct *vma, +static inline bool clear_flush_young_ptes_notify(struct vm_area_struct *vm= a, unsigned long addr, pte_t *ptep, unsigned int nr) { - int young; + bool young; =20 young =3D clear_flush_young_ptes(vma, addr, ptep, nr); young |=3D mmu_notifier_clear_flush_young(vma->vm_mm, addr, @@ -1842,30 +1842,30 @@ static inline int clear_flush_young_ptes_notify(str= uct vm_area_struct *vma, return young; } =20 -static inline int pmdp_clear_flush_young_notify(struct vm_area_struct *vma, +static inline bool pmdp_clear_flush_young_notify(struct vm_area_struct *vm= a, unsigned long addr, pmd_t *pmdp) { - int young; + bool young; =20 young =3D pmdp_clear_flush_young(vma, addr, pmdp); young |=3D mmu_notifier_clear_flush_young(vma->vm_mm, addr, addr + PMD_SI= ZE); return young; } =20 -static inline int test_and_clear_young_ptes_notify(struct vm_area_struct *= vma, +static inline bool test_and_clear_young_ptes_notify(struct vm_area_struct = *vma, unsigned long addr, pte_t *ptep, unsigned int nr) { - int young; + bool young; =20 young =3D test_and_clear_young_ptes(vma, addr, ptep, nr); young |=3D mmu_notifier_clear_young(vma->vm_mm, addr, addr + nr * PAGE_SI= ZE); return young; } =20 -static inline int pmdp_test_and_clear_young_notify(struct vm_area_struct *= vma, +static inline bool pmdp_test_and_clear_young_notify(struct vm_area_struct = *vma, unsigned long addr, pmd_t *pmdp) { - int young; + bool young; =20 young =3D pmdp_test_and_clear_young(vma, addr, pmdp); young |=3D mmu_notifier_clear_young(vma->vm_mm, addr, addr + PMD_SIZE); diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 2502474b83b6..dc6f78d559f7 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -364,12 +364,12 @@ void __mmu_notifier_release(struct mm_struct *mm) * unmap the address and return 1 or 0 depending if the mapping previously * existed or not. */ -int __mmu_notifier_clear_flush_young(struct mm_struct *mm, - unsigned long start, - unsigned long end) +bool __mmu_notifier_clear_flush_young(struct mm_struct *mm, + unsigned long start, unsigned long end) { struct mmu_notifier *subscription; - int young =3D 0, id; + bool young =3D false; + int id; =20 id =3D srcu_read_lock(&srcu); hlist_for_each_entry_srcu(subscription, @@ -384,12 +384,12 @@ int __mmu_notifier_clear_flush_young(struct mm_struct= *mm, return young; } =20 -int __mmu_notifier_clear_young(struct mm_struct *mm, - unsigned long start, - unsigned long end) +bool __mmu_notifier_clear_young(struct mm_struct *mm, + unsigned long start, unsigned long end) { struct mmu_notifier *subscription; - int young =3D 0, id; + bool young =3D false; + int id; =20 id =3D srcu_read_lock(&srcu); hlist_for_each_entry_srcu(subscription, @@ -404,11 +404,12 @@ int __mmu_notifier_clear_young(struct mm_struct *mm, return young; } =20 -int __mmu_notifier_test_young(struct mm_struct *mm, - unsigned long address) +bool __mmu_notifier_test_young(struct mm_struct *mm, + unsigned long address) { struct mmu_notifier *subscription; - int young =3D 0, id; + bool young =3D false; + int id; =20 id =3D srcu_read_lock(&srcu); hlist_for_each_entry_srcu(subscription, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d0ab29672c71..82433f46c438 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -646,11 +646,9 @@ static __always_inline kvm_mn_ret_t kvm_handle_hva_ran= ge(struct kvm *kvm, return r; } =20 -static __always_inline int kvm_age_hva_range(struct mmu_notifier *mn, - unsigned long start, - unsigned long end, - gfn_handler_t handler, - bool flush_on_ret) +static __always_inline bool kvm_age_hva_range(struct mmu_notifier *mn, + unsigned long start, unsigned long end, gfn_handler_t handler, + bool flush_on_ret) { struct kvm *kvm =3D mmu_notifier_to_kvm(mn); const struct kvm_mmu_notifier_range range =3D { @@ -666,10 +664,8 @@ static __always_inline int kvm_age_hva_range(struct mm= u_notifier *mn, return kvm_handle_hva_range(kvm, &range).ret; } =20 -static __always_inline int kvm_age_hva_range_no_flush(struct mmu_notifier = *mn, - unsigned long start, - unsigned long end, - gfn_handler_t handler) +static __always_inline bool kvm_age_hva_range_no_flush(struct mmu_notifier= *mn, + unsigned long start, unsigned long end, gfn_handler_t handler) { return kvm_age_hva_range(mn, start, end, handler, false); } @@ -829,10 +825,8 @@ static void kvm_mmu_notifier_invalidate_range_end(stru= ct mmu_notifier *mn, rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait); } =20 -static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end) +static bool kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn, + struct mm_struct *mm, unsigned long start, unsigned long end) { trace_kvm_age_hva(start, end); =20 @@ -840,10 +834,8 @@ static int kvm_mmu_notifier_clear_flush_young(struct m= mu_notifier *mn, !IS_ENABLED(CONFIG_KVM_ELIDE_TLB_FLUSH_IF_YOUNG)); } =20 -static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end) +static bool kvm_mmu_notifier_clear_young(struct mmu_notifier *mn, + struct mm_struct *mm, unsigned long start, unsigned long end) { trace_kvm_age_hva(start, end); =20 @@ -863,9 +855,8 @@ static int kvm_mmu_notifier_clear_young(struct mmu_noti= fier *mn, return kvm_age_hva_range_no_flush(mn, start, end, kvm_age_gfn); } =20 -static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long address) +static bool kvm_mmu_notifier_test_young(struct mmu_notifier *mn, + struct mm_struct *mm, unsigned long address) { trace_kvm_test_age_hva(address); =20 --=20 2.47.3