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.
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
include/linux/mmu_notifier.h | 76 +++++++++++++++++-------------------
mm/internal.h | 16 ++++----
mm/mmu_notifier.c | 20 +++++-----
virt/kvm/kvm_main.c | 40 +++++++++----------
4 files changed, 72 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);
/*
* 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);
/*
* 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);
/*
* invalidate_range_start() and invalidate_range_end() must be
@@ -376,14 +376,12 @@ mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub,
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_struct *mm)
__mmu_notifier_release(mm);
}
-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;
}
-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;
}
-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;
}
static inline void
@@ -552,24 +548,22 @@ static inline void mmu_notifier_release(struct mm_struct *mm)
{
}
-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;
}
-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;
}
-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;
}
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(struct vm_area_struct *vma,
}
#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 *vma,
unsigned long addr, pte_t *ptep, unsigned int nr)
{
- int young;
+ bool young;
young = clear_flush_young_ptes(vma, addr, ptep, nr);
young |= mmu_notifier_clear_flush_young(vma->vm_mm, addr,
@@ -1842,30 +1842,30 @@ static inline int clear_flush_young_ptes_notify(struct vm_area_struct *vma,
return young;
}
-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 *vma,
unsigned long addr, pmd_t *pmdp)
{
- int young;
+ bool young;
young = pmdp_clear_flush_young(vma, addr, pmdp);
young |= mmu_notifier_clear_flush_young(vma->vm_mm, addr, addr + PMD_SIZE);
return young;
}
-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;
young = test_and_clear_young_ptes(vma, addr, ptep, nr);
young |= mmu_notifier_clear_young(vma->vm_mm, addr, addr + nr * PAGE_SIZE);
return young;
}
-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;
young = pmdp_test_and_clear_young(vma, addr, pmdp);
young |= 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..3e3e7e727ba2 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -364,12 +364,11 @@ 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 = 0, id;
+ bool young = false, id;
id = srcu_read_lock(&srcu);
hlist_for_each_entry_srcu(subscription,
@@ -384,12 +383,11 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
return young;
}
-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 = 0, id;
+ bool young = false, id;
id = srcu_read_lock(&srcu);
hlist_for_each_entry_srcu(subscription,
@@ -404,11 +402,11 @@ int __mmu_notifier_clear_young(struct mm_struct *mm,
return young;
}
-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 = 0, id;
+ bool young = false, id;
id = 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..6bcfc1b3021d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -646,11 +646,11 @@ static __always_inline kvm_mn_ret_t kvm_handle_hva_range(struct kvm *kvm,
return r;
}
-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 = mmu_notifier_to_kvm(mn);
const struct kvm_mmu_notifier_range range = {
@@ -666,10 +666,10 @@ static __always_inline int kvm_age_hva_range(struct mmu_notifier *mn,
return kvm_handle_hva_range(kvm, &range).ret;
}
-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 +829,10 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait);
}
-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);
@@ -840,10 +840,10 @@ static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
!IS_ENABLED(CONFIG_KVM_ELIDE_TLB_FLUSH_IF_YOUNG));
}
-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);
@@ -863,9 +863,9 @@ static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
return kvm_age_hva_range_no_flush(mn, start, end, kvm_age_gfn);
}
-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);
--
2.47.3On Thu, Mar 19, 2026 at 11:24:05AM +0800, Baolin Wang wrote:
> 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.
>
> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
I can see KVM is the only user for the mmu_notifier_ops clear_flush_young,
clear_young and test_young hooks, which map to
kvm_mmu_notifier_[clear_flush,clear,test]_young() functions, and you have
updated them all.
So this LGTM with nits below, and so (with nits addressed as per the other R-b
tags :):
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Thanks for doing this! Int as bool is a pet peeve of mine :))
Cheers, Lorenzo
> ---
> include/linux/mmu_notifier.h | 76 +++++++++++++++++-------------------
> mm/internal.h | 16 ++++----
> mm/mmu_notifier.c | 20 +++++-----
> virt/kvm/kvm_main.c | 40 +++++++++----------
> 4 files changed, 72 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);
>
> /*
> * 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);
>
> /*
> * 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);
>
> /*
> * invalidate_range_start() and invalidate_range_end() must be
> @@ -376,14 +376,12 @@ mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub,
>
> 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,
I mean damn, at this point maybe it's legit to drop the surrounding externs here
too? But maybe not :))
> @@ -403,30 +401,28 @@ static inline void mmu_notifier_release(struct mm_struct *mm)
> __mmu_notifier_release(mm);
> }
>
> -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;
> }
>
> -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;
> }
>
> -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;
> }
>
> static inline void
> @@ -552,24 +548,22 @@ static inline void mmu_notifier_release(struct mm_struct *mm)
> {
> }
>
> -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;
> }
>
> -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;
> }
>
> -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;
> }
>
> 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(struct vm_area_struct *vma,
> }
>
> #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 *vma,
> unsigned long addr, pte_t *ptep, unsigned int nr)
> {
> - int young;
> + bool young;
>
> young = clear_flush_young_ptes(vma, addr, ptep, nr);
> young |= mmu_notifier_clear_flush_young(vma->vm_mm, addr,
> @@ -1842,30 +1842,30 @@ static inline int clear_flush_young_ptes_notify(struct vm_area_struct *vma,
> return young;
> }
>
> -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 *vma,
> unsigned long addr, pmd_t *pmdp)
> {
> - int young;
> + bool young;
>
> young = pmdp_clear_flush_young(vma, addr, pmdp);
> young |= mmu_notifier_clear_flush_young(vma->vm_mm, addr, addr + PMD_SIZE);
> return young;
> }
>
> -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;
>
> young = test_and_clear_young_ptes(vma, addr, ptep, nr);
> young |= mmu_notifier_clear_young(vma->vm_mm, addr, addr + nr * PAGE_SIZE);
> return young;
> }
>
> -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;
>
> young = pmdp_test_and_clear_young(vma, addr, pmdp);
> young |= 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..3e3e7e727ba2 100644
> --- a/mm/mmu_notifier.c
> +++ b/mm/mmu_notifier.c
> @@ -364,12 +364,11 @@ 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 = 0, id;
> + bool young = false, id;
>
> id = srcu_read_lock(&srcu);
> hlist_for_each_entry_srcu(subscription,
> @@ -384,12 +383,11 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
> return young;
> }
>
> -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 = 0, id;
> + bool young = false, id;
>
> id = srcu_read_lock(&srcu);
> hlist_for_each_entry_srcu(subscription,
> @@ -404,11 +402,11 @@ int __mmu_notifier_clear_young(struct mm_struct *mm,
> return young;
> }
>
> -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 = 0, id;
> + bool young = false, id;
>
> id = 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..6bcfc1b3021d 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -646,11 +646,11 @@ static __always_inline kvm_mn_ret_t kvm_handle_hva_range(struct kvm *kvm,
> return r;
> }
>
> -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)
Can we please fix this terrrible indentation while we're here :)?
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)
Would be nicer, thanks!
> {
> struct kvm *kvm = mmu_notifier_to_kvm(mn);
> const struct kvm_mmu_notifier_range range = {
> @@ -666,10 +666,10 @@ static __always_inline int kvm_age_hva_range(struct mmu_notifier *mn,
> return kvm_handle_hva_range(kvm, &range).ret;
> }
>
> -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)
Same indentation comment here.
> {
> return kvm_age_hva_range(mn, start, end, handler, false);
> }
> @@ -829,10 +829,10 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
> rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait);
> }
>
> -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)
Same indentation comment here.
> {
> trace_kvm_age_hva(start, end);
>
> @@ -840,10 +840,10 @@ static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
> !IS_ENABLED(CONFIG_KVM_ELIDE_TLB_FLUSH_IF_YOUNG));
> }
>
> -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)
Same indentation comment here.
> {
> trace_kvm_age_hva(start, end);
>
> @@ -863,9 +863,9 @@ static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
> return kvm_age_hva_range_no_flush(mn, start, end, kvm_age_gfn);
> }
>
> -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)
Same indentation comment here.
> {
> trace_kvm_test_age_hva(address);
>
> --
> 2.47.3
>
On 3/19/26 7:39 PM, Lorenzo Stoakes (Oracle) wrote:
> On Thu, Mar 19, 2026 at 11:24:05AM +0800, Baolin Wang wrote:
>> 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.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
>
> I can see KVM is the only user for the mmu_notifier_ops clear_flush_young,
> clear_young and test_young hooks, which map to
> kvm_mmu_notifier_[clear_flush,clear,test]_young() functions, and you have
> updated them all.
Yes.
> So this LGTM with nits below, and so (with nits addressed as per the other R-b
> tags :):
>
> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
>
> Thanks for doing this! Int as bool is a pet peeve of mine :))
Thanks for reviewing.
>> include/linux/mmu_notifier.h | 76 +++++++++++++++++-------------------
>> mm/internal.h | 16 ++++----
>> mm/mmu_notifier.c | 20 +++++-----
>> virt/kvm/kvm_main.c | 40 +++++++++----------
>> 4 files changed, 72 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);
>>
>> /*
>> * 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);
>>
>> /*
>> * 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);
>>
>> /*
>> * invalidate_range_start() and invalidate_range_end() must be
>> @@ -376,14 +376,12 @@ mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub,
>>
>> 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,
>
> I mean damn, at this point maybe it's legit to drop the surrounding externs here
> too? But maybe not :))
I prefer to leave the others as is:)
[snip]
>>
>> -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)
>
> Can we please fix this terrrible indentation while we're here :)?
>
> 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)
>
> Would be nicer, thanks!
Will do if KVM maintainers are also happy with this.
On Fri, Mar 20, 2026, Baolin Wang wrote: > > > -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) > > > > Can we please fix this terrrible indentation while we're here :)? > > > > 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) > > > > Would be nicer, thanks! No, please keep this as-is. KVM's preferred style is exactly this (and I personally find mm's style much harder to parse).
On 4/4/26 7:12 AM, Sean Christopherson wrote: > On Fri, Mar 20, 2026, Baolin Wang wrote: >>>> -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) >>> >>> Can we please fix this terrrible indentation while we're here :)? >>> >>> 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) >>> >>> Would be nicer, thanks! > > No, please keep this as-is. KVM's preferred style is exactly this (and I personally > find mm's style much harder to parse). Um, Andrew has already queued v2[1] into the mm-stable branch. Do you want me to send a follow-up patch to restore the original KVM coding style? [1] https://lore.kernel.org/all/cover.1774075004.git.baolin.wang@linux.alibaba.com/T/#u
On Tue, Apr 07, 2026, Baolin Wang wrote: > On 4/4/26 7:12 AM, Sean Christopherson wrote: > > On Fri, Mar 20, 2026, Baolin Wang wrote: > > > > > -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) > > > > > > > > Can we please fix this terrrible indentation while we're here :)? > > > > > > > > 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) > > > > > > > > Would be nicer, thanks! > > > > No, please keep this as-is. KVM's preferred style is exactly this (and I personally > > find mm's style much harder to parse). > > Um, Andrew has already queued v2[1] into the mm-stable branch. Do you want > me to send a follow-up patch to restore the original KVM coding style? Nah, not worth the churn. Thanks though!
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