Commit b3a3ca8c authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: Add new tracepoint: trace_ext4_da_write_pages() 



Add a new tracepoint which shows the pages that will be written using
write_cache_pages() by ext4_da_writepages().

Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent de89de6e

fs/ext4/ext4.h

+15 −0
Original line number Diff line number Diff line
@@ -113,6 +113,21 @@ struct ext4_allocation_request { 
	unsigned int flags;

};



/*

 * For delayed allocation tracking

 */

struct mpage_da_data {

	struct inode *inode;

	sector_t b_blocknr;		/* start block number of extent */

	size_t b_size;			/* size of extent */

	unsigned long b_state;		/* state of the extent */

	unsigned long first_page, next_page;	/* extent of pages */

	struct writeback_control *wbc;

	int io_done;

	int pages_written;

	int retval;

};



/*

 * Special inodes numbers

 */

fs/ext4/inode.c

+1 −12
Original line number Diff line number Diff line
@@ -1875,18 +1875,6 @@ static void ext4_da_page_release_reservation(struct page *page, 
 * Delayed allocation stuff

 */



struct mpage_da_data {

	struct inode *inode;

	sector_t b_blocknr;		/* start block number of extent */

	size_t b_size;			/* size of extent */

	unsigned long b_state;		/* state of the extent */

	unsigned long first_page, next_page;	/* extent of pages */

	struct writeback_control *wbc;

	int io_done;

	int pages_written;

	int retval;

};



/*

 * mpage_da_submit_io - walks through extent of pages and try to write

 * them with writepage() call back
@@ -2863,6 +2851,7 @@ static int ext4_da_writepages(struct address_space *mapping, 
			mpd.io_done = 1;

			ret = MPAGE_DA_EXTENT_TAIL;

		}

		trace_ext4_da_write_pages(inode, &mpd);

		wbc->nr_to_write -= mpd.pages_written;



		ext4_journal_stop(handle);

include/trace/events/ext4.h

+34 −0
Original line number Diff line number Diff line
@@ -251,6 +251,40 @@ TRACE_EVENT(ext4_da_writepages, 
		  __entry->range_cyclic)

);



TRACE_EVENT(ext4_da_write_pages,

	TP_PROTO(struct inode *inode, struct mpage_da_data *mpd),



	TP_ARGS(inode, mpd),



	TP_STRUCT__entry(

		__field(	dev_t,	dev			)

		__field(	ino_t,	ino			)

		__field(	__u64,	b_blocknr		)

		__field(	__u32,	b_size			)

		__field(	__u32,	b_state			)

		__field(	unsigned long,	first_page	)

		__field(	int,	io_done			)

		__field(	int,	pages_written		)

	),



	TP_fast_assign(

		__entry->dev		= inode->i_sb->s_dev;

		__entry->ino		= inode->i_ino;

		__entry->b_blocknr	= mpd->b_blocknr;

		__entry->b_size		= mpd->b_size;

		__entry->b_state	= mpd->b_state;

		__entry->first_page	= mpd->first_page;

		__entry->io_done	= mpd->io_done;

		__entry->pages_written	= mpd->pages_written;

	),



	TP_printk("dev %s ino %lu b_blocknr %llu b_size %u b_state 0x%04x first_page %lu io_done %d pages_written %d",

		  jbd2_dev_to_name(__entry->dev), __entry->ino,

		  __entry->b_blocknr, __entry->b_size,

		  __entry->b_state, __entry->first_page,

		  __entry->io_done, __entry->pages_written)

);



TRACE_EVENT(ext4_da_writepages_result,

	TP_PROTO(struct inode *inode, struct writeback_control *wbc,

			int ret, int pages_written),