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 <[email protected]>
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) <[email protected]>
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.
