[PATCH 3/6] mm:split the drop cache operation into a function

From: Liang Li
Date: Mon Jun 13 2016 - 05:53:39 EST


Put the drop caches operation in a new function and export it, then
wen can reuse it later.

Signed-off-by: Liang Li <liang.z.li@xxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
Cc: Amit Shah <amit.shah@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/drop_caches.c | 22 ++++++++++++++--------
include/linux/mm.h | 1 +
2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index d72d52b..977dc71 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -50,14 +50,7 @@ int drop_caches_sysctl_handler(struct ctl_table *table, int write,
if (write) {
static int stfu;

- if (sysctl_drop_caches & 1) {
- iterate_supers(drop_pagecache_sb, NULL);
- count_vm_event(DROP_PAGECACHE);
- }
- if (sysctl_drop_caches & 2) {
- drop_slab();
- count_vm_event(DROP_SLAB);
- }
+ drop_caches(sysctl_drop_caches);
if (!stfu) {
pr_info("%s (%d): drop_caches: %d\n",
current->comm, task_pid_nr(current),
@@ -67,3 +60,16 @@ int drop_caches_sysctl_handler(struct ctl_table *table, int write,
}
return 0;
}
+
+void drop_caches(int drop_ctl)
+{
+ if (drop_ctl & 1) {
+ iterate_supers(drop_pagecache_sb, NULL);
+ count_vm_event(DROP_PAGECACHE);
+ }
+ if (drop_ctl & 2) {
+ drop_slab();
+ count_vm_event(DROP_SLAB);
+ }
+}
+EXPORT_SYMBOL_GPL(drop_caches);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5df5feb..e22e315 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2263,6 +2263,7 @@ static inline int in_gate_area(struct mm_struct *mm, unsigned long addr)
extern int sysctl_drop_caches;
int drop_caches_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
+void drop_caches(int drop_ctl);
#endif

void drop_slab(void);
--
1.9.1