Re: [PATCH 1/4] xfs: split the page fault trace event

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Oct 29, 2024 at 04:11:57PM +0100, Christoph Hellwig wrote:
> Split the xfs_filemap_fault trace event into separate ones for read and
> write faults and move them into the applicable locations.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Yay nice split!
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/xfs/xfs_file.c  |  8 ++++++--
>  fs/xfs/xfs_trace.h | 20 ++++++++++++--------
>  2 files changed, 18 insertions(+), 10 deletions(-)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index b19916b11fd5..20f7f92b8867 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1425,6 +1425,8 @@ xfs_dax_read_fault(
>  	struct xfs_inode	*ip = XFS_I(file_inode(vmf->vma->vm_file));
>  	vm_fault_t		ret;
>  
> +	trace_xfs_read_fault(ip, order);
> +
>  	xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
>  	ret = xfs_dax_fault_locked(vmf, order, false);
>  	xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
> @@ -1442,6 +1444,8 @@ xfs_write_fault(
>  	unsigned int		lock_mode = XFS_MMAPLOCK_SHARED;
>  	vm_fault_t		ret;
>  
> +	trace_xfs_write_fault(ip, order);
> +
>  	sb_start_pagefault(inode->i_sb);
>  	file_update_time(vmf->vma->vm_file);
>  
> @@ -1485,12 +1489,12 @@ __xfs_filemap_fault(
>  {
>  	struct inode		*inode = file_inode(vmf->vma->vm_file);
>  
> -	trace_xfs_filemap_fault(XFS_I(inode), order, write_fault);
> -
>  	if (write_fault)
>  		return xfs_write_fault(vmf, order);
>  	if (IS_DAX(inode))
>  		return xfs_dax_read_fault(vmf, order);
> +
> +	trace_xfs_read_fault(XFS_I(inode), order);
>  	return filemap_fault(vmf);
>  }
>  
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index ee9f0b1f548d..efc4aae295aa 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -827,28 +827,32 @@ DEFINE_INODE_EVENT(xfs_inode_inactivating);
>  TRACE_DEFINE_ENUM(XFS_REFC_DOMAIN_SHARED);
>  TRACE_DEFINE_ENUM(XFS_REFC_DOMAIN_COW);
>  
> -TRACE_EVENT(xfs_filemap_fault,
> -	TP_PROTO(struct xfs_inode *ip, unsigned int order, bool write_fault),
> -	TP_ARGS(ip, order, write_fault),
> +DECLARE_EVENT_CLASS(xfs_fault_class,
> +	TP_PROTO(struct xfs_inode *ip, unsigned int order),
> +	TP_ARGS(ip, order),
>  	TP_STRUCT__entry(
>  		__field(dev_t, dev)
>  		__field(xfs_ino_t, ino)
>  		__field(unsigned int, order)
> -		__field(bool, write_fault)
>  	),
>  	TP_fast_assign(
>  		__entry->dev = VFS_I(ip)->i_sb->s_dev;
>  		__entry->ino = ip->i_ino;
>  		__entry->order = order;
> -		__entry->write_fault = write_fault;
>  	),
> -	TP_printk("dev %d:%d ino 0x%llx order %u write_fault %d",
> +	TP_printk("dev %d:%d ino 0x%llx order %u",
>  		  MAJOR(__entry->dev), MINOR(__entry->dev),
>  		  __entry->ino,
> -		  __entry->order,
> -		  __entry->write_fault)
> +		  __entry->order)
>  )
>  
> +#define DEFINE_FAULT_EVENT(name) \
> +DEFINE_EVENT(xfs_fault_class, name, \
> +	TP_PROTO(struct xfs_inode *ip, unsigned int order), \
> +	TP_ARGS(ip, order))
> +DEFINE_FAULT_EVENT(xfs_read_fault);
> +DEFINE_FAULT_EVENT(xfs_write_fault);
> +
>  DECLARE_EVENT_CLASS(xfs_iref_class,
>  	TP_PROTO(struct xfs_inode *ip, unsigned long caller_ip),
>  	TP_ARGS(ip, caller_ip),
> -- 
> 2.45.2
> 
>