From 0e175a1835ffc979e55787774e58ec79e41957d7 Mon Sep 17 00:00:00 2001 From: Curt Wohlgemuth Date: Fri, 7 Oct 2011 21:54:10 -0600 Subject: writeback: Add a 'reason' to wb_writeback_work This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: Jan Kara Signed-off-by: Curt Wohlgemuth Signed-off-by: Wu Fengguang --- include/linux/backing-dev.h | 3 ++- include/linux/writeback.h | 32 ++++++++++++++++++++++++++------ include/trace/events/writeback.h | 14 ++++++++++---- 3 files changed, 38 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index c3b92010d894..b1038bd686ac 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -118,7 +118,8 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev); void bdi_unregister(struct backing_dev_info *bdi); int bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int); -void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages); +void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages, + enum wb_reason reason); void bdi_start_background_writeback(struct backing_dev_info *bdi); int bdi_writeback_thread(void *data); int bdi_has_dirty_io(struct backing_dev_info *bdi); diff --git a/include/linux/writeback.h b/include/linux/writeback.h index ddb4652cb337..a378c295851f 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -38,6 +38,23 @@ enum writeback_sync_modes { WB_SYNC_ALL, /* Wait on every mapping */ }; +/* + * why some writeback work was initiated + */ +enum wb_reason { + WB_REASON_BACKGROUND, + WB_REASON_TRY_TO_FREE_PAGES, + WB_REASON_SYNC, + WB_REASON_PERIODIC, + WB_REASON_LAPTOP_TIMER, + WB_REASON_FREE_MORE_MEM, + WB_REASON_FS_FREE_SPACE, + WB_REASON_FORKER_THREAD, + + WB_REASON_MAX, +}; +extern const char *wb_reason_name[]; + /* * A control structure which tells the writeback code what to do. These are * always on the stack, and hence need no locking. They are always initialised @@ -69,14 +86,17 @@ struct writeback_control { */ struct bdi_writeback; int inode_wait(void *); -void writeback_inodes_sb(struct super_block *); -void writeback_inodes_sb_nr(struct super_block *, unsigned long nr); -int writeback_inodes_sb_if_idle(struct super_block *); -int writeback_inodes_sb_nr_if_idle(struct super_block *, unsigned long nr); +void writeback_inodes_sb(struct super_block *, enum wb_reason reason); +void writeback_inodes_sb_nr(struct super_block *, unsigned long nr, + enum wb_reason reason); +int writeback_inodes_sb_if_idle(struct super_block *, enum wb_reason reason); +int writeback_inodes_sb_nr_if_idle(struct super_block *, unsigned long nr, + enum wb_reason reason); void sync_inodes_sb(struct super_block *); -long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages); +long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages, + enum wb_reason reason); long wb_do_writeback(struct bdi_writeback *wb, int force_wait); -void wakeup_flusher_threads(long nr_pages); +void wakeup_flusher_threads(long nr_pages, enum wb_reason reason); /* writeback.h requires fs.h; it, too, is not included from here. */ static inline void wait_on_inode(struct inode *inode) diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index 1261db3916cc..b99caa8b780c 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -34,6 +34,7 @@ DECLARE_EVENT_CLASS(writeback_work_class, __field(int, for_kupdate) __field(int, range_cyclic) __field(int, for_background) + __field(int, reason) ), TP_fast_assign( strncpy(__entry->name, dev_name(bdi->dev), 32); @@ -43,16 +44,18 @@ DECLARE_EVENT_CLASS(writeback_work_class, __entry->for_kupdate = work->for_kupdate; __entry->range_cyclic = work->range_cyclic; __entry->for_background = work->for_background; + __entry->reason = work->reason; ), TP_printk("bdi %s: sb_dev %d:%d nr_pages=%ld sync_mode=%d " - "kupdate=%d range_cyclic=%d background=%d", + "kupdate=%d range_cyclic=%d background=%d reason=%s", __entry->name, MAJOR(__entry->sb_dev), MINOR(__entry->sb_dev), __entry->nr_pages, __entry->sync_mode, __entry->for_kupdate, __entry->range_cyclic, - __entry->for_background + __entry->for_background, + wb_reason_name[__entry->reason] ) ); #define DEFINE_WRITEBACK_WORK_EVENT(name) \ @@ -165,6 +168,7 @@ TRACE_EVENT(writeback_queue_io, __field(unsigned long, older) __field(long, age) __field(int, moved) + __field(int, reason) ), TP_fast_assign( unsigned long *older_than_this = work->older_than_this; @@ -173,12 +177,14 @@ TRACE_EVENT(writeback_queue_io, __entry->age = older_than_this ? (jiffies - *older_than_this) * 1000 / HZ : -1; __entry->moved = moved; + __entry->reason = work->reason; ), - TP_printk("bdi %s: older=%lu age=%ld enqueue=%d", + TP_printk("bdi %s: older=%lu age=%ld enqueue=%d reason=%s", __entry->name, __entry->older, /* older_than_this in jiffies */ __entry->age, /* older_than_this in relative milliseconds */ - __entry->moved) + __entry->moved, + wb_reason_name[__entry->reason]) ); TRACE_EVENT(global_dirty_state, -- cgit v1.2.3