From 6b4afdd794783fe515b50838aa36591e3feea990 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Wed, 2 Apr 2014 15:34:36 +0900 Subject: f2fs: introduce f2fs_issue_flush to avoid redundant flush issue Some storage devices show relatively high latencies to complete cache_flush commands, even though their normal IO speed is prettry much high. In such the case, it needs to merge cache_flush commands as much as possible to avoid issuing them redundantly. So, this patch introduces a mount option, "-o flush_merge", to mitigate such the overhead. If this option is enabled by user, F2FS merges the cache_flush commands and then issues just one cache_flush on behalf of them. Once the single command is finished, F2FS sends a completion signal to all the pending threads. Note that, this option can be used under a workload consisting of very intensive concurrent fsync calls, while the storage handles cache_flush commands slowly. Signed-off-by: Jaegeuk Kim --- fs/f2fs/f2fs.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'fs/f2fs/f2fs.h') diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 1e3d869b60cd..2ecac8312359 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -40,6 +40,7 @@ #define F2FS_MOUNT_DISABLE_EXT_IDENTIFY 0x00000040 #define F2FS_MOUNT_INLINE_XATTR 0x00000080 #define F2FS_MOUNT_INLINE_DATA 0x00000100 +#define F2FS_MOUNT_FLUSH_MERGE 0x00000200 #define clear_opt(sbi, option) (sbi->mount_opt.opt &= ~F2FS_MOUNT_##option) #define set_opt(sbi, option) (sbi->mount_opt.opt |= F2FS_MOUNT_##option) @@ -316,6 +317,12 @@ enum { NO_CHECK_TYPE }; +struct flush_cmd { + struct flush_cmd *next; + struct completion wait; + int ret; +}; + struct f2fs_sm_info { struct sit_info *sit_info; /* whole segment information */ struct free_segmap_info *free_info; /* free segment information */ @@ -344,6 +351,14 @@ struct f2fs_sm_info { unsigned int ipu_policy; /* in-place-update policy */ unsigned int min_ipu_util; /* in-place-update threshold */ + + /* for flush command control */ + struct task_struct *f2fs_issue_flush; /* flush thread */ + wait_queue_head_t flush_wait_queue; /* waiting queue for wake-up */ + struct flush_cmd *issue_list; /* list for command issue */ + struct flush_cmd *dispatch_list; /* list for command dispatch */ + spinlock_t issue_lock; /* for issue list lock */ + struct flush_cmd *issue_tail; /* list tail of issue list */ }; /* @@ -1160,6 +1175,7 @@ void destroy_node_manager_caches(void); */ void f2fs_balance_fs(struct f2fs_sb_info *); void f2fs_balance_fs_bg(struct f2fs_sb_info *); +int f2fs_issue_flush(struct f2fs_sb_info *); void invalidate_blocks(struct f2fs_sb_info *, block_t); void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t); void clear_prefree_segments(struct f2fs_sb_info *); -- cgit v1.2.3