Commit f9bc3a07 authored May 08, 2017 by Ross Zwisler Committed by Linus Torvalds May 08, 2017

dax: add tracepoint to dax_writeback_one()

Add a tracepoint to dax_writeback_one(), following the same logging
conventions as the rest of DAX.

Here is an example range writeback which ends up flushing one PMD and
one PTE:

  test-1265  [003] ....
   496.615250: dax_writeback_range: dev 259:0 ino 0x1003 pgoff 0x0-0x7ffffffffffff

  test-1265  [003] ....
   496.616263: dax_writeback_one: dev 259:0 ino 0x1003 pgoff 0x0 pglen 0x200

  test-1265  [003] ....
   496.616270: dax_writeback_one: dev 259:0 ino 0x1003 pgoff 0x305 pglen 0x1

  test-1265  [003] ....
   496.616272: dax_writeback_range_done: dev 259:0 ino 0x1003 pgoff 0x0-0x7ffffffffffff

[akpm@linux-foundation.org: struct blk_dax_ctl has disappeared]
Link: http://lkml.kernel.org/r/20170221195116.13278-6-ross.zwisler@linux.intel.com


Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent d14a3f48

fs/dax.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -823,6 +823,7 @@ static int dax_writeback_one(struct block_device *bdev,
		spin_lock_irq(&mapping->tree_lock);
		radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_DIRTY);
		spin_unlock_irq(&mapping->tree_lock);
		trace_dax_writeback_one(mapping->host, index, size >> PAGE_SHIFT);
		dax_unlock:
		dax_read_unlock(id);
		put_locked_mapping_entry(mapping, index, entry);

include/trace/events/fs_dax.h

+24 −0

Original line number	Diff line number	Diff line
		@@ -226,6 +226,30 @@ DEFINE_EVENT(dax_writeback_range_class, name, \
		DEFINE_WRITEBACK_RANGE_EVENT(dax_writeback_range);
		DEFINE_WRITEBACK_RANGE_EVENT(dax_writeback_range_done);

		TRACE_EVENT(dax_writeback_one,
		TP_PROTO(struct inode *inode, pgoff_t pgoff, pgoff_t pglen),
		TP_ARGS(inode, pgoff, pglen),
		TP_STRUCT__entry(
		__field(unsigned long, ino)
		__field(pgoff_t, pgoff)
		__field(pgoff_t, pglen)
		__field(dev_t, dev)
		),
		TP_fast_assign(
		__entry->dev = inode->i_sb->s_dev;
		__entry->ino = inode->i_ino;
		__entry->pgoff = pgoff;
		__entry->pglen = pglen;
		),
		TP_printk("dev %d:%d ino %#lx pgoff %#lx pglen %#lx",
		MAJOR(__entry->dev),
		MINOR(__entry->dev),
		__entry->ino,
		__entry->pgoff,
		__entry->pglen
		)
		)

		#endif /* _TRACE_FS_DAX_H */

		/* This part must be outside protection */

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