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

[Jonathan Helman]

On 04/13/2018 03:07 PM, Michael S. Tsirkin wrote:
> 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")

Sure. Thanks.

Jon

> > > 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.