From a7eeb823854c4ab19765a25fabbda07fe27be177 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Tue, 28 Mar 2017 18:18:50 +0800 Subject: f2fs: use bitmap in discard_entry This patch changes to use bitmap instead of extent in struct discard_entry to indicate discard range in one segment, for fragmented space, this implementation can save memory footprint. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/segment.c | 72 ++++++++++++++++++++++++++++++------------------------- 1 file changed, 40 insertions(+), 32 deletions(-) (limited to 'fs/f2fs/segment.c') diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index d5413afdd3da..12d2aa7032bb 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -962,32 +962,6 @@ static int f2fs_issue_discard(struct f2fs_sb_info *sbi, return err; } -static void __add_discard_entry(struct f2fs_sb_info *sbi, - struct cp_control *cpc, struct seg_entry *se, - unsigned int start, unsigned int end) -{ - struct list_head *head = &SM_I(sbi)->dcc_info->discard_entry_list; - struct discard_entry *new, *last; - - if (!list_empty(head)) { - last = list_last_entry(head, struct discard_entry, list); - if (START_BLOCK(sbi, cpc->trim_start) + start == - last->blkaddr + last->len && - last->len < MAX_DISCARD_BLOCKS(sbi)) { - last->len += end - start; - goto done; - } - } - - new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS); - INIT_LIST_HEAD(&new->list); - new->blkaddr = START_BLOCK(sbi, cpc->trim_start) + start; - new->len = end - start; - list_add_tail(&new->list, head); -done: - SM_I(sbi)->dcc_info->nr_discards += end - start; -} - static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc, bool check_only) { @@ -1000,6 +974,8 @@ static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc, unsigned long *dmap = SIT_I(sbi)->tmp_map; unsigned int start = 0, end = -1; bool force = (cpc->reason == CP_DISCARD); + struct discard_entry *de = NULL; + struct list_head *head = &SM_I(sbi)->dcc_info->discard_entry_list; int i; if (se->valid_blocks == max_blocks || !f2fs_discard_en(sbi)) @@ -1031,7 +1007,17 @@ static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc, if (check_only) return true; - __add_discard_entry(sbi, cpc, se, start, end); + if (!de) { + de = f2fs_kmem_cache_alloc(discard_entry_slab, + GFP_F2FS_ZERO); + de->start_blkaddr = START_BLOCK(sbi, cpc->trim_start); + list_add_tail(&de->list, head); + } + + for (i = start; i < end; i++) + __set_bit_le(i, (void *)de->discard_map); + + SM_I(sbi)->dcc_info->nr_discards += end - start; } return false; } @@ -1117,13 +1103,35 @@ next: /* send small discards */ list_for_each_entry_safe(entry, this, head, list) { - if (force && entry->len < cpc->trim_minlen) - goto skip; - f2fs_issue_discard(sbi, entry->blkaddr, entry->len); - cpc->trimmed += entry->len; + unsigned int cur_pos = 0, next_pos, len, total_len = 0; + bool is_valid = test_bit_le(0, entry->discard_map); + +find_next: + if (is_valid) { + next_pos = find_next_zero_bit_le(entry->discard_map, + sbi->blocks_per_seg, cur_pos); + len = next_pos - cur_pos; + + if (force && len < cpc->trim_minlen) + goto skip; + + f2fs_issue_discard(sbi, entry->start_blkaddr + cur_pos, + len); + cpc->trimmed += len; + total_len += len; + } else { + next_pos = find_next_bit_le(entry->discard_map, + sbi->blocks_per_seg, cur_pos); + } skip: + cur_pos = next_pos; + is_valid = !is_valid; + + if (cur_pos < sbi->blocks_per_seg) + goto find_next; + list_del(&entry->list); - SM_I(sbi)->dcc_info->nr_discards -= entry->len; + SM_I(sbi)->dcc_info->nr_discards -= total_len; kmem_cache_free(discard_entry_slab, entry); } } -- cgit v1.2.3