Commit 121e213e authored by Dave Chinner's avatar Dave Chinner Committed by Dave Chinner
Browse files

xfs: add tracepoints to readpage calls 



This allows us to see page cache driven readahead in action as it
passes through XFS. This helps to understand buffered read
throughput problems such as readahead IO IO sizes being too small
for the underlying device to reach max throughput.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent a841b64d

fs/xfs/xfs_aops.c

+2 −0
Original line number Diff line number Diff line
@@ -1917,6 +1917,7 @@ xfs_vm_readpage( 
	struct file		*unused,

	struct page		*page)

{

	trace_xfs_vm_readpage(page->mapping->host, 1);

	return mpage_readpage(page, xfs_get_blocks);

}
@@ -1927,6 +1928,7 @@ xfs_vm_readpages( 
	struct list_head	*pages,

	unsigned		nr_pages)

{

	trace_xfs_vm_readpages(mapping->host, nr_pages);

	return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks);

}

fs/xfs/xfs_trace.h

+26 −0
Original line number Diff line number Diff line
@@ -1222,6 +1222,32 @@ DEFINE_PAGE_EVENT(xfs_writepage); 
DEFINE_PAGE_EVENT(xfs_releasepage);

DEFINE_PAGE_EVENT(xfs_invalidatepage);



DECLARE_EVENT_CLASS(xfs_readpage_class,

	TP_PROTO(struct inode *inode, int nr_pages),

	TP_ARGS(inode, nr_pages),

	TP_STRUCT__entry(

		__field(dev_t, dev)

		__field(xfs_ino_t, ino)

		__field(int, nr_pages)

	),

	TP_fast_assign(

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

		__entry->ino = inode->i_ino;

		__entry->nr_pages = nr_pages;

	),

	TP_printk("dev %d:%d ino 0x%llx nr_pages %d",

		  MAJOR(__entry->dev), MINOR(__entry->dev),

		  __entry->ino,

		  __entry->nr_pages)

)



#define DEFINE_READPAGE_EVENT(name)		\

DEFINE_EVENT(xfs_readpage_class, name,	\

	TP_PROTO(struct inode *inode, int nr_pages), \

	TP_ARGS(inode, nr_pages))

DEFINE_READPAGE_EVENT(xfs_vm_readpage);

DEFINE_READPAGE_EVENT(xfs_vm_readpages);



DECLARE_EVENT_CLASS(xfs_imap_class,

	TP_PROTO(struct xfs_inode *ip, xfs_off_t offset, ssize_t count,

		 int type, struct xfs_bmbt_irec *irec),

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