f2fs: avoid small data writes by skipping writepages
This patch introduces nr_pages_to_skip(sbi, type) to determine writepages can
be skipped.
The dentry, node, and meta pages can be conrolled by F2FS without breaking the
FS consistency.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index c3d5e36..bbd9761 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -664,3 +664,22 @@
struct request_queue *q = bdev_get_queue(bdev);
return SECTOR_TO_BLOCK(sbi, queue_max_sectors(q));
}
+
+/*
+ * It is very important to gather dirty pages and write at once, so that we can
+ * submit a big bio without interfering other data writes.
+ * By default, 512 pages for directory data,
+ * 512 pages (2MB) * 3 for three types of nodes, and
+ * max_bio_blocks for meta are set.
+ */
+static inline int nr_pages_to_skip(struct f2fs_sb_info *sbi, int type)
+{
+ if (type == DATA)
+ return sbi->blocks_per_seg;
+ else if (type == NODE)
+ return 3 * sbi->blocks_per_seg;
+ else if (type == META)
+ return MAX_BIO_BLOCKS(max_hw_blocks(sbi));
+ else
+ return 0;
+}