Commit e589c2c4 authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: control not to exceed # of cached nat entries 



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

Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 29710bcf

fs/f2fs/node.c

+4 −0
Original line number Diff line number Diff line
@@ -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;

fs/f2fs/node.h

+7 −0
Original line number Diff line number Diff line
@@ -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 */

fs/f2fs/segment.c

+5 −0
Original line number Diff line number Diff line
@@ -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.