f2fs: control not to exceed # of cached nat entries

This is to avoid cache entry management overhead including radix tree.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim 2016-06-02 15:24:24 -07:00
parent 29710bcf94
commit e589c2c477
3 changed files with 16 additions and 0 deletions

View File

@ -52,6 +52,10 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
mem_size = (nm_i->nat_cnt * sizeof(struct nat_entry)) >>
PAGE_SHIFT;
res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
if (excess_cached_nats(sbi))
res = false;
if (nm_i->nat_cnt > DEF_NAT_CACHE_THRESHOLD)
res = false;
} else if (type == DIRTY_DENTS) {
if (sbi->sb->s_bdi->wb.dirty_exceeded)
return false;

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@ -27,6 +27,8 @@
/* control dirty nats ratio threshold (default: 10% over max nid count) */
#define DEF_DIRTY_NAT_RATIO_THRESHOLD 10
/* control total # of nats */
#define DEF_NAT_CACHE_THRESHOLD 100000
/* vector size for gang look-up from nat cache that consists of radix tree */
#define NATVEC_SIZE 64
@ -126,6 +128,11 @@ static inline bool excess_dirty_nats(struct f2fs_sb_info *sbi)
NM_I(sbi)->dirty_nats_ratio / 100;
}
static inline bool excess_cached_nats(struct f2fs_sb_info *sbi)
{
return NM_I(sbi)->nat_cnt >= DEF_NAT_CACHE_THRESHOLD;
}
enum mem_type {
FREE_NIDS, /* indicates the free nid list */
NAT_ENTRIES, /* indicates the cached nat entry */

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@ -345,6 +345,11 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
{
if (!need)
return;
/* balance_fs_bg is able to be pending */
if (excess_cached_nats(sbi))
f2fs_balance_fs_bg(sbi);
/*
* We should do GC or end up with checkpoint, if there are so many dirty
* dir/node pages without enough free segments.