[f2fs-dev][PATCH 3/4 v2] f2fs: readahead contiguous current summary blocks in checkpoint

From: Chao Yu
Date: Tue Dec 09 2014 - 01:22:54 EST


Let's add readahead code for reading contiguous compact/normal summary blocks
in checkpoint, then we will gain better performance in mount procedure.

Changes from v1
o remove inappropriate 'unlikely' in npages_for_summary_flush.

Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
---
fs/f2fs/checkpoint.c | 2 +-
fs/f2fs/f2fs.h | 2 +-
fs/f2fs/segment.c | 21 ++++++++++++++++++---
3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index b2d5431..226f980 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -923,7 +923,7 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
ckpt->next_free_nid = cpu_to_le32(last_nid);

/* 2 cp + n data seg summary + orphan inode blocks */
- data_sum_blocks = npages_for_summary_flush(sbi);
+ data_sum_blocks = npages_for_summary_flush(sbi, false);
if (data_sum_blocks < NR_CURSEG_DATA_TYPE)
set_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
else
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f60b817..1d36ff5 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1401,7 +1401,7 @@ void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t);
void clear_prefree_segments(struct f2fs_sb_info *);
void release_discard_addrs(struct f2fs_sb_info *);
void discard_next_dnode(struct f2fs_sb_info *, block_t);
-int npages_for_summary_flush(struct f2fs_sb_info *);
+int npages_for_summary_flush(struct f2fs_sb_info *, bool);
void allocate_new_segments(struct f2fs_sb_info *);
int f2fs_trim_fs(struct f2fs_sb_info *, struct fstrim_range *);
struct page *get_sum_page(struct f2fs_sb_info *, unsigned int);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 42607a6..e287e45 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -735,7 +735,7 @@ static void __add_sum_entry(struct f2fs_sb_info *sbi, int type,
/*
* Calculate the number of current summary pages for writing
*/
-int npages_for_summary_flush(struct f2fs_sb_info *sbi)
+int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra)
{
int valid_sum_count = 0;
int i, sum_in_page;
@@ -743,8 +743,13 @@ int npages_for_summary_flush(struct f2fs_sb_info *sbi)
for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
if (sbi->ckpt->alloc_type[i] == SSR)
valid_sum_count += sbi->blocks_per_seg;
- else
- valid_sum_count += curseg_blkoff(sbi, i);
+ else {
+ if (for_ra)
+ valid_sum_count += le16_to_cpu(
+ F2FS_CKPT(sbi)->cur_data_blkoff[i]);
+ else
+ valid_sum_count += curseg_blkoff(sbi, i);
+ }
}

sum_in_page = (PAGE_CACHE_SIZE - 2 * SUM_JOURNAL_SIZE -
@@ -1450,12 +1455,22 @@ static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
int err;

if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_COMPACT_SUM_FLAG)) {
+ int npages = npages_for_summary_flush(sbi, true);
+
+ if (npages >= 2)
+ ra_meta_pages(sbi, start_sum_block(sbi), npages,
+ META_CP);
+
/* restore for compacted data summary */
if (read_compacted_summaries(sbi))
return -EINVAL;
type = CURSEG_HOT_NODE;
}

+ if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_UMOUNT_FLAG))
+ ra_meta_pages(sbi, sum_blk_addr(sbi, NR_CURSEG_TYPE, type),
+ NR_CURSEG_TYPE - type, META_CP);
+
for (; type <= CURSEG_COLD_NODE; type++) {
err = read_normal_summaries(sbi, type);
if (err)
--
2.1.2


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