xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

f2fs: introduce a shrinker for mounted fs

Browse Source 
This patch introduces a shrinker targeting to reduce memory footprint consumed
by a number of in-memory f2fs data structures.

In addition, it newly adds:
 - sbi->umount_mutex to avoid data races on shrinker and put_super
 - sbi->shruinker_run_no to not revisit objects

Note that the basic implementation was copied from fs/ubifs/shrinker.c

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim
2015-06-19 12:01:21 -07:00
parent 244f4fc1c5
commit 2658e50de6
4 changed files with 148 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

104
fs/f2fs/shrinker.c Normal file
View File

@@ -0,0 +1,104 @@
/*
* f2fs shrinker support
* the basic infra was copied from fs/ubifs/shrinker.c
*
* Copyright (c) 2015 Motorola Mobility
* Copyright (c) 2015 Jaegeuk Kim <jaegeuk@kernel.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/fs.h>
#include <linux/f2fs_fs.h>
#include "f2fs.h"
static LIST_HEAD(f2fs_list);
static DEFINE_SPINLOCK(f2fs_list_lock);
static unsigned int shrinker_run_no;
unsigned long f2fs_shrink_count(struct shrinker *shrink,
struct shrink_control *sc)
{
struct f2fs_sb_info *sbi;
struct list_head *p;
unsigned long count = 0;
spin_lock(&f2fs_list_lock);
p = f2fs_list.next;
while (p != &f2fs_list) {
sbi = list_entry(p, struct f2fs_sb_info, s_list);
/* stop f2fs_put_super */
if (!mutex_trylock(&sbi->umount_mutex)) {
p = p->next;
continue;
}
spin_unlock(&f2fs_list_lock);
/* TODO: count # of objects */
spin_lock(&f2fs_list_lock);
p = p->next;
mutex_unlock(&sbi->umount_mutex);
}
spin_unlock(&f2fs_list_lock);
return count;
}
unsigned long f2fs_shrink_scan(struct shrinker *shrink,
struct shrink_control *sc)
{
unsigned long nr = sc->nr_to_scan;
struct f2fs_sb_info *sbi;
struct list_head *p;
unsigned int run_no;
unsigned long freed = 0;
spin_lock(&f2fs_list_lock);
do {
run_no = ++shrinker_run_no;
} while (run_no == 0);
p = f2fs_list.next;
while (p != &f2fs_list) {
sbi = list_entry(p, struct f2fs_sb_info, s_list);
if (sbi->shrinker_run_no == run_no)
break;
/* stop f2fs_put_super */
if (!mutex_trylock(&sbi->umount_mutex)) {
p = p->next;
continue;
}
spin_unlock(&f2fs_list_lock);
sbi->shrinker_run_no = run_no;
/* TODO: shrink caches */
spin_lock(&f2fs_list_lock);
p = p->next;
list_move_tail(&sbi->s_list, &f2fs_list);
mutex_unlock(&sbi->umount_mutex);
if (freed >= nr)
break;
}
spin_unlock(&f2fs_list_lock);
return freed;
}
void f2fs_join_shrinker(struct f2fs_sb_info *sbi)
{
spin_lock(&f2fs_list_lock);
list_add_tail(&sbi->s_list, &f2fs_list);
spin_unlock(&f2fs_list_lock);
}
void f2fs_leave_shrinker(struct f2fs_sb_info *sbi)
{
spin_lock(&f2fs_list_lock);
list_del(&sbi->s_list);
spin_unlock(&f2fs_list_lock);
}