Re: [PATCH v2 3/6] dax: add tracepoint infrastructure, PMD tracing

[Ross Zwisler]

On Thu, Dec 01, 2016 at 09:16:28AM -0500, Steven Rostedt wrote:
> On Wed, 30 Nov 2016 16:45:30 -0700
> Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> wrote:
> 
> 
> > --- /dev/null
> > +++ b/include/trace/events/fs_dax.h
> > @@ -0,0 +1,68 @@
> > +#undef TRACE_SYSTEM
> > +#define TRACE_SYSTEM fs_dax
> > +
> > +#if !defined(_TRACE_FS_DAX_H) || defined(TRACE_HEADER_MULTI_READ)
> > +#define _TRACE_FS_DAX_H
> > +
> > +#include <linux/tracepoint.h>
> > +
> > +DECLARE_EVENT_CLASS(dax_pmd_fault_class,
> > +	TP_PROTO(struct inode *inode, struct vm_area_struct *vma,
> > +		unsigned long address, unsigned int flags, pgoff_t pgoff,
> > +		pgoff_t max_pgoff, int result),
> > +	TP_ARGS(inode, vma, address, flags, pgoff, max_pgoff, result),
> > +	TP_STRUCT__entry(
> > +		__field(dev_t, dev)
> > +		__field(unsigned long, ino)
> > +		__field(unsigned long, vm_start)
> > +		__field(unsigned long, vm_end)
> > +		__field(unsigned long, vm_flags)
> > +		__field(unsigned long, address)
> > +		__field(unsigned int, flags)
> > +		__field(pgoff_t, pgoff)
> > +		__field(pgoff_t, max_pgoff)
> > +		__field(int, result)
> 
> For better compaction, I would put flags and result together, as they
> are both ints. Otherwise, you'll probably have 4 empty bytes after
> flags.

Sure, will do for v3.