From 3f5000693f80e014fa577b67b93a0de945a4338d Mon Sep 17 00:00:00 2001 From: zijun_hu Date: Mon, 12 Dec 2016 16:42:17 -0800 Subject: [PATCH] mm/vmalloc.c: simplify /proc/vmallocinfo implementation Many seq_file helpers exist for simplifying implementation of virtual files especially, for /proc nodes. however, the helpers for iteration over list_head are available but aren't adopted to implement /proc/vmallocinfo currently. Simplify /proc/vmallocinfo implementation by using existing seq_file helpers. Link: http://lkml.kernel.org/r/57FDF2E5.1000201@zoho.com Signed-off-by: zijun_hu Acked-by: Michal Hocko Cc: David Rientjes Cc: Tejun Heo Cc: Ingo Molnar Cc: Joonsoo Kim Cc: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 27 +++++---------------------- 1 file changed, 5 insertions(+), 22 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index f2481cb4e6b2..e73948afac70 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2574,32 +2574,13 @@ 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) @@ -2634,9 +2615,11 @@ 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(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. -- 2.20.1