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b8559dc242
During free nid allocation, in order to do preallocation, we will tag free
nid entry as allocated one and still leave it in free nid list, for other
allocators who want to grab free nids, it needs to traverse the free nid
list for lookup. It becomes overhead in scenario of allocating free nid
intensively by multithreads.
This patch splits free nid list to two list: {free,alloc}_nid_list, to
keep free nids and preallocated free nids separately, after that, traverse
latency will be gone, besides split nid_cnt for separate statistic.
Additionally, introduce __insert_nid_to_list and __remove_nid_from_list for
cleanup.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: modify f2fs_bug_on to avoid needless branches]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
142 lines
3.3 KiB
C
142 lines
3.3 KiB
C
/*
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* f2fs shrinker support
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* the basic infra was copied from fs/ubifs/shrinker.c
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*
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* Copyright (c) 2015 Motorola Mobility
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* Copyright (c) 2015 Jaegeuk Kim <jaegeuk@kernel.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/fs.h>
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#include <linux/f2fs_fs.h>
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#include "f2fs.h"
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#include "node.h"
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static LIST_HEAD(f2fs_list);
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static DEFINE_SPINLOCK(f2fs_list_lock);
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static unsigned int shrinker_run_no;
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static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
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{
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return NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
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}
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static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
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{
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if (NM_I(sbi)->nid_cnt[FREE_NID_LIST] > MAX_FREE_NIDS)
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return NM_I(sbi)->nid_cnt[FREE_NID_LIST] - MAX_FREE_NIDS;
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return 0;
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}
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static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi)
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{
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return atomic_read(&sbi->total_zombie_tree) +
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atomic_read(&sbi->total_ext_node);
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}
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unsigned long f2fs_shrink_count(struct shrinker *shrink,
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struct shrink_control *sc)
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{
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struct f2fs_sb_info *sbi;
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struct list_head *p;
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unsigned long count = 0;
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spin_lock(&f2fs_list_lock);
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p = f2fs_list.next;
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while (p != &f2fs_list) {
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sbi = list_entry(p, struct f2fs_sb_info, s_list);
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/* stop f2fs_put_super */
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if (!mutex_trylock(&sbi->umount_mutex)) {
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p = p->next;
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continue;
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}
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spin_unlock(&f2fs_list_lock);
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/* count extent cache entries */
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count += __count_extent_cache(sbi);
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/* shrink clean nat cache entries */
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count += __count_nat_entries(sbi);
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/* count free nids cache entries */
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count += __count_free_nids(sbi);
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spin_lock(&f2fs_list_lock);
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p = p->next;
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mutex_unlock(&sbi->umount_mutex);
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}
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spin_unlock(&f2fs_list_lock);
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return count;
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}
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unsigned long f2fs_shrink_scan(struct shrinker *shrink,
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struct shrink_control *sc)
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{
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unsigned long nr = sc->nr_to_scan;
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struct f2fs_sb_info *sbi;
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struct list_head *p;
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unsigned int run_no;
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unsigned long freed = 0;
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spin_lock(&f2fs_list_lock);
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do {
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run_no = ++shrinker_run_no;
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} while (run_no == 0);
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p = f2fs_list.next;
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while (p != &f2fs_list) {
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sbi = list_entry(p, struct f2fs_sb_info, s_list);
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if (sbi->shrinker_run_no == run_no)
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break;
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/* stop f2fs_put_super */
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if (!mutex_trylock(&sbi->umount_mutex)) {
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p = p->next;
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continue;
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}
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spin_unlock(&f2fs_list_lock);
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sbi->shrinker_run_no = run_no;
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/* shrink extent cache entries */
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freed += f2fs_shrink_extent_tree(sbi, nr >> 1);
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/* shrink clean nat cache entries */
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if (freed < nr)
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freed += try_to_free_nats(sbi, nr - freed);
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/* shrink free nids cache entries */
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if (freed < nr)
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freed += try_to_free_nids(sbi, nr - freed);
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spin_lock(&f2fs_list_lock);
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p = p->next;
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list_move_tail(&sbi->s_list, &f2fs_list);
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mutex_unlock(&sbi->umount_mutex);
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if (freed >= nr)
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break;
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}
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spin_unlock(&f2fs_list_lock);
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return freed;
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}
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void f2fs_join_shrinker(struct f2fs_sb_info *sbi)
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{
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spin_lock(&f2fs_list_lock);
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list_add_tail(&sbi->s_list, &f2fs_list);
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spin_unlock(&f2fs_list_lock);
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}
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void f2fs_leave_shrinker(struct f2fs_sb_info *sbi)
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{
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f2fs_shrink_extent_tree(sbi, __count_extent_cache(sbi));
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spin_lock(&f2fs_list_lock);
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list_del(&sbi->s_list);
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spin_unlock(&f2fs_list_lock);
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}
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