Re: [PATCH] virtio_balloon: add array of stat names

[Michael S. Tsirkin]

On Fri, Apr 13, 2018 at 11:53:31AM -0700, Jonathan Helman wrote:
> 
> 
> On 04/13/2018 06:44 AM, Michael S. Tsirkin wrote:
> > Jason Wang points out that it's vary hard for users to build an array of
> 
> s/vary/very
> 
> > stat names. The naive thing is to use VIRTIO_BALLOON_S_NR but that
> > breaks if we add more stats.
> > 
> > Let's add an array of reasonably readable names.
> 
> Thanks for doing this, this is goodness. Clients of this interface will now
> only require a modification to their internal copy of the header file (if
> they have one), rather than updating their string array as well.
> 
> > 
> > Fixes: 6c64fe7f2 ("virtio_balloon: export hugetlb page allocation counts")
> 
> I think this is a tad bit confusing since the only way you'd know why this
> patch "fixes" 6c64fe7f2 is by reading the LKML archives and finding Jason's
> comment.

So

... add more stats as recently by commit 6c64fe7f2 ("virtio_balloon: export hugetlb page allocation counts")




> > Cc: Jason Wang <jasowang@xxxxxxxxxx>
> > Cc: Jonathan Helman <jonathan.helman@xxxxxxxxxx>, > Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> 
> Reviewed-by: Jonathan Helman <jonathan.helman@xxxxxxxxxx>
> 
> > ---
> >   include/uapi/linux/virtio_balloon.h | 15 +++++++++++++++
> >   1 file changed, 15 insertions(+)
> > 
> > diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
> > index 9e02137..1477c17 100644
> > --- a/include/uapi/linux/virtio_balloon.h
> > +++ b/include/uapi/linux/virtio_balloon.h
> > @@ -64,6 +64,21 @@ struct virtio_balloon_config {
> >   #define VIRTIO_BALLOON_S_HTLB_PGFAIL   9  /* Hugetlb page allocation failures */
> >   #define VIRTIO_BALLOON_S_NR       10
> > +#define VIRTIO_BALLOON_S_NAMES_WITH_PREFIX(VIRTIO_BALLOON_S_NAMES_prefix) { \
> > +	VIRTIO_BALLOON_S_NAMES_prefix "swap-in", \
> > +	VIRTIO_BALLOON_S_NAMES_prefix "swap-out", \
> > +	VIRTIO_BALLOON_S_NAMES_prefix "major-faults", \
> > +	VIRTIO_BALLOON_S_NAMES_prefix "minor-faults", \
> > +	VIRTIO_BALLOON_S_NAMES_prefix "free-memory", \
> > +	VIRTIO_BALLOON_S_NAMES_prefix "total-memory", \
> > +	VIRTIO_BALLOON_S_NAMES_prefix "available-memory", \
> > +	VIRTIO_BALLOON_S_NAMES_prefix "disk-caches", \
> > +	VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-allocations", \
> > +	VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-failures" \ > +}
> > +
> > +#define VIRTIO_BALLOON_S_NAMES VIRTIO_BALLOON_S_NAMES_WITH_PREFIX("")
> > +
> >   /*
> >    * Memory statistics structure.
> >    * Driver fills an array of these structures and passes to device.
> >