2013-07-09 03:59:10

by Gu Zheng

[permalink] [raw]
Subject: [PATCH] f2fs: Modify do_garbage_collect() to collect all the segs in once

Current do_garbage_collect() collect per segment per time. If there are more
than one segments in section, we need to call do_garbage_collect() many times to
collect all the segments(current is a for loop). We can move the loop into the
do_garbage_collect(), so that we can collect all the segs of section in one time.

Signed-off-by: Gu Zheng <[email protected]>
---
fs/f2fs/gc.c | 59 ++++++++++++++++++++++++++++++++-------------------------
1 files changed, 33 insertions(+), 26 deletions(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 35f9b1a..ccde9f7 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -634,42 +634,50 @@ static int __get_victim(struct f2fs_sb_info *sbi, unsigned
int *victim,
return ret;
}

-static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
- struct list_head *ilist, int gc_type)
+static void do_garbage_collect(struct f2fs_sb_info *sbi,
+ unsigned int start_segno, struct list_head *ilist, int gc_type)
{
- struct page *sum_page;
- struct f2fs_summary_block *sum;
- struct blk_plug plug;
+ unsigned int segno = start_segno;

- /* read segment summary of victim */
- sum_page = get_sum_page(sbi, segno);
- if (IS_ERR(sum_page))
- return;
+ for (; sbi->segs_per_sec--; segno++) {
+ struct page *sum_page;
+ struct f2fs_summary_block *sum;
+ struct blk_plug plug;

- blk_start_plug(&plug);
+ /* read segment summary of victim */
+ sum_page = get_sum_page(sbi, segno);
+ if (IS_ERR(sum_page))
+ continue;

- sum = page_address(sum_page);
+ blk_start_plug(&plug);

- switch (GET_SUM_TYPE((&sum->footer))) {
- case SUM_TYPE_NODE:
- gc_node_segment(sbi, sum->entries, segno, gc_type);
- break;
- case SUM_TYPE_DATA:
- gc_data_segment(sbi, sum->entries, ilist, segno, gc_type);
- break;
- }
- blk_finish_plug(&plug);
+ sum = page_address(sum_page);

- stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)));
- stat_inc_call_count(sbi->stat_info);
+ switch (GET_SUM_TYPE((&sum->footer))) {
+ case SUM_TYPE_NODE:
+ gc_node_segment(sbi, sum->entries,
+ segno, gc_type);
+ break;
+ case SUM_TYPE_DATA:
+ gc_data_segment(sbi, sum->entries, ilist,
+ segno, gc_type);
+ break;
+ default:
+ BUG();
+ }
+ blk_finish_plug(&plug);
+
+ stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)));
+ stat_inc_call_count(sbi->stat_info);

- f2fs_put_page(sum_page, 1);
+ f2fs_put_page(sum_page, 1);
+ }
}

int f2fs_gc(struct f2fs_sb_info *sbi)
{
struct list_head ilist;
- unsigned int segno, i;
+ unsigned int segno;
int gc_type = BG_GC;
int nfree = 0;
int ret = -1;
@@ -688,8 +696,7 @@ gc_more:
goto stop;
ret = 0;

- for (i = 0; i < sbi->segs_per_sec; i++)
- do_garbage_collect(sbi, segno + i, &ilist, gc_type);
+ do_garbage_collect(sbi, segno, &ilist, gc_type);

if (gc_type == FG_GC) {
sbi->cur_victim_sec = NULL_SEGNO;
--
1.7.7