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mm/vmalloc.c: simplify /proc/vmallocinfo implementation

PATCH Superseded zijun_hu 2 participants 3 messages Sep 21, 2016

Subsystems (2)
Memory management vmalloc

v1 of 2 Superseded Latest is v2 →

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zijun_hu

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#0 lore raw

PATCH 2/5 mm/vmalloc.c: simplify /proc/vmallocinfo implementation

From: zijun_hu <[email protected]>

simplify /proc/vmallocinfo implementation via seq_file helpers for list_head

Signed-off-by zijun_hu <[email protected]>
---
 mm/vmalloc.c | 27 +++++----------------------
 1 file changed, 5 insertions(+), 22 deletions(-)
mm/vmalloc.c +5 -22
index cc6ecd6..a125ae8 100644
@@ -2576,32 +2576,13 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
 static void *s_start(struct seq_file *m, loff_t *pos)
 	__acquires(&vmap_area_lock)
 {
-	loff_t n = *pos;
-	struct vmap_area *va;
-
 	spin_lock(&vmap_area_lock);
-	va = list_first_entry(&vmap_area_list, typeof(*va), list);
-	while (n > 0 && &va->list != &vmap_area_list) {
-		n--;
-		va = list_next_entry(va, list);
-	}
-	if (!n && &va->list != &vmap_area_list)
-		return va;
-
-	return NULL;
-
+	return seq_list_start(&vmap_area_list, *pos);
 }
 
 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
 {
-	struct vmap_area *va = p, *next;
-
-	++*pos;
-	next = list_next_entry(va, list);
-	if (&next->list != &vmap_area_list)
-		return next;
-
-	return NULL;
+	return seq_list_next(p, &vmap_area_list, pos);
 }
 
 static void s_stop(struct seq_file *m, void *p)

@@ -2636,9 +2617,11 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
 
 static int s_show(struct seq_file *m, void *p)
 {
-	struct vmap_area *va = p;
+	struct vmap_area *va;
 	struct vm_struct *v;
 
+	va = list_entry((struct list_head *)p, struct vmap_area, list);
+
 	/*
 	 * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
 	 * behalf of vmap area is being tear down or vm_map_ram allocation.
Signature · 1 line
1.9.1
#1 lore raw
Quoted 40 lines · zijun_hu
mm/vmalloc.c +2 -21
index cc6ecd6..a125ae8 100644
@@ -2576,32 +2576,13 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
 static void *s_start(struct seq_file *m, loff_t *pos)
 	__acquires(&vmap_area_lock)
 {
-	loff_t n = *pos;
-	struct vmap_area *va;
-
 	spin_lock(&vmap_area_lock);
-	va = list_first_entry(&vmap_area_list, typeof(*va), list);
-	while (n > 0 && &va->list != &vmap_area_list) {
-		n--;
-		va = list_next_entry(va, list);
-	}
-	if (!n && &va->list != &vmap_area_list)
-		return va;
-
-	return NULL;
-
+	return seq_list_start(&vmap_area_list, *pos);
 }
 
 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
 {
-	struct vmap_area *va = p, *next;
-
-	++*pos;
-	next = list_next_entry(va, list);
-	if (&next->list != &vmap_area_list)
-		return next;
-
-	return NULL;
+	return seq_list_next(p, &vmap_area_list, pos);
 }
 
 static void s_stop(struct seq_file *m, void *p)

mm/vmalloc.c static void show_numa_info(struct seq_file *m, struct vm_struct *v) · line 2623

Quoted 8 lines
mm/vmalloc.c +2 -1
@@ -2636,9 +2617,11 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
 
 static int s_show(struct seq_file *m, void *p)
 {
-	struct vmap_area *va = p;
+	struct vmap_area *va;
 	struct vm_struct *v;
 
+	va = list_entry((struct list_head *)p, struct vmap_area, list);

Looks good other than no cast is neccessary above.

The patches in this series seem to be unrelated to each other, they shouldn't be numbered in order since there's no dependence. Just individual patches are fine.

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author
#2 lore raw
Quoted 49 lines · David Rientjes
Quoted 47 lines · zijun_hu
mm/vmalloc.c +3 -22
index cc6ecd6..a125ae8 100644
@@ -2576,32 +2576,13 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
 static void *s_start(struct seq_file *m, loff_t *pos)
 	__acquires(&vmap_area_lock)
 {
-	loff_t n = *pos;
-	struct vmap_area *va;
-
 	spin_lock(&vmap_area_lock);
-	va = list_first_entry(&vmap_area_list, typeof(*va), list);
-	while (n > 0 && &va->list != &vmap_area_list) {
-		n--;
-		va = list_next_entry(va, list);
-	}
-	if (!n && &va->list != &vmap_area_list)
-		return va;
-
-	return NULL;
-
+	return seq_list_start(&vmap_area_list, *pos);
 }
 
 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
 {
-	struct vmap_area *va = p, *next;
-
-	++*pos;
-	next = list_next_entry(va, list);
-	if (&next->list != &vmap_area_list)
-		return next;
-
-	return NULL;
+	return seq_list_next(p, &vmap_area_list, pos);
 }
 
 static void s_stop(struct seq_file *m, void *p)

@@ -2636,9 +2617,11 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
 
 static int s_show(struct seq_file *m, void *p)
 {
-	struct vmap_area *va = p;
+	struct vmap_area *va;
 	struct vm_struct *v;
Quoted 3 lines

mm/vmalloc.c static void show_numa_info(struct seq_file *m, struct vm_struct *v) · line 2623

Quoted 1 line
mm/vmalloc.c +1 -0
+	va = list_entry((struct list_head *)p, struct vmap_area, list);

Looks good other than no cast is neccessary above.

you are right, it will correct it
i refer to show_timer()@fs/proc/base.c plainly and ignore that redundant cast

Quoted 5 lines

The patches in this series seem to be unrelated to each other, they shouldn't be numbered in order since there's no dependence. Just individual patches are fine.

you are right, i will provide a individual patch finnally