diff mbox series

[RFC,v2,1/5] mm/mmu_notifier: introduce a new mmu notifier flag MMU_NOTIFIER_RANGE_NUMA

Message ID 20230810085743.25977-1-yan.y.zhao@intel.com (mailing list archive)
State New
Headers show
Series Reduce NUMA balance caused TLB-shootdowns in a VM | expand

Commit Message

Yan Zhao Aug. 10, 2023, 8:57 a.m. UTC 
Introduce a new mmu notifier flag MMU_NOTIFIER_RANGE_NUMA to indicate the
notification of MMU_NOTIFY_PROTECTION_VMA is for NUMA balance purpose
specifically.

So that, the subscriber of mmu notifier, like KVM, can recognize this
type of notification and do numa protection specific operations in the
handler.

Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
---
 include/linux/mmu_notifier.h | 1 +
 mm/mprotect.c                | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 64a3e051c3c4..a6dc829a4bce 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -60,6 +60,7 @@  enum mmu_notifier_event {
 };
 
 #define MMU_NOTIFIER_RANGE_BLOCKABLE (1 << 0)
+#define MMU_NOTIFIER_RANGE_NUMA (1 << 1)
 
 struct mmu_notifier_ops {
 	/*
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 6f658d483704..cb99a7d66467 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -381,7 +381,9 @@  static inline long change_pmd_range(struct mmu_gather *tlb,
 		/* invoke the mmu notifier if the pmd is populated */
 		if (!range.start) {
 			mmu_notifier_range_init(&range,
-				MMU_NOTIFY_PROTECTION_VMA, 0,
+				MMU_NOTIFY_PROTECTION_VMA,
+				cp_flags & MM_CP_PROT_NUMA ?
+				MMU_NOTIFIER_RANGE_NUMA : 0,
 				vma->vm_mm, addr, end);
 			mmu_notifier_invalidate_range_start(&range);
 		}