[PATCH] mm/vmalloc.c: avoid repeatedly requiring lock unnecessarily

[Baoquan He]

By moving setup_vmalloc_vm() into alloc_vmap_area(), we can reduce
requiring lock one time in short time.

Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
---
 mm/vmalloc.c | 23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index aeee71349157..6bda3c06b484 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1848,7 +1848,10 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 				unsigned long align,
 				unsigned long vstart, unsigned long vend,
 				int node, gfp_t gfp_mask,
-				unsigned long va_flags)
+				unsigned long va_flags,
+				struct vm_struct *vm,
+				unsigned long vm_flags,
+				const void *caller)
 {
 	struct vmap_node *vn;
 	struct vmap_area *va;
@@ -1915,6 +1918,8 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 
 	spin_lock(&vn->busy.lock);
 	insert_vmap_area(va, &vn->busy.root, &vn->busy.head);
+	if (!(va_flags & VMAP_RAM) && vm)
+		setup_vmalloc_vm(vm, va, vm_flags, caller);
 	spin_unlock(&vn->busy.lock);
 
 	BUG_ON(!IS_ALIGNED(va->va_start, align));
@@ -2947,7 +2952,7 @@ void __init vm_area_register_early(struct vm_struct *vm, size_t align)
 	kasan_populate_early_vm_area_shadow(vm->addr, vm->size);
 }
 
-static inline void setup_vmalloc_vm_locked(struct vm_struct *vm,
+static inline void setup_vmalloc_vm(struct vm_struct *vm,
 	struct vmap_area *va, unsigned long flags, const void *caller)
 {
 	vm->flags = flags;
@@ -2957,16 +2962,6 @@ static inline void setup_vmalloc_vm_locked(struct vm_struct *vm,
 	va->vm = vm;
 }
 
-static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
-			      unsigned long flags, const void *caller)
-{
-	struct vmap_node *vn = addr_to_node(va->va_start);
-
-	spin_lock(&vn->busy.lock);
-	setup_vmalloc_vm_locked(vm, va, flags, caller);
-	spin_unlock(&vn->busy.lock);
-}
-
 static void clear_vm_uninitialized_flag(struct vm_struct *vm)
 {
 	/*
@@ -3009,8 +3004,6 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
 		return NULL;
 	}
 
-	setup_vmalloc_vm(area, va, flags, caller);
-
 	/*
 	 * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a
 	 * best-effort approach, as they can be mapped outside of vmalloc code.
@@ -4586,7 +4579,7 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
 
 		spin_lock(&vn->busy.lock);
 		insert_vmap_area(vas[area], &vn->busy.root, &vn->busy.head);
-		setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC,
+		setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
 				 pcpu_get_vm_areas);
 		spin_unlock(&vn->busy.lock);
 	}
-- 
2.41.0