Re: [PATCH] virtio_balloon: export huge page allocation statistics

[Jonathan Helman]

On 02/27/2018 07:20 AM, Michael S. Tsirkin wrote:
> On Fri, Feb 16, 2018 at 09:44:32PM -0800, Jonathan Helman wrote:
> > Export statistics for successful and failed huge page allocations
> > from the virtio balloon driver. These 2 stats come directly from
> > the vm_events HTLB_BUDDY_PGALLOC and HTLB_BUDDY_PGALLOC_FAIL.
> > Signed-off-by: Jonathan Helman <jonathan.helman@xxxxxxxxxx>
>
> Any host/guest intergace changes need to be copied to
> the virtio TC mailing list (subscriber-only, sorry about that):
> virtio-dev@xxxxxxxxxxxxxxxxxxxx

Sorry, will do on v2.

> > ---
> >   drivers/virtio/virtio_balloon.c     | 6 ++++++
> >   include/uapi/linux/virtio_balloon.h | 4 +++-
> >   2 files changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> > index dfe5684..6b237e3 100644
> > --- a/drivers/virtio/virtio_balloon.c
> > +++ b/drivers/virtio/virtio_balloon.c
> > @@ -272,6 +272,12 @@ static unsigned int update_balloon_stats(struct virtio_balloon *vb)
> >   				pages_to_bytes(events[PSWPOUT]));
> >   	update_stat(vb, idx++, VIRTIO_BALLOON_S_MAJFLT, events[PGMAJFAULT]);
> >   	update_stat(vb, idx++, VIRTIO_BALLOON_S_MINFLT, events[PGFAULT]);
> > +#ifdef CONFIG_HUGETLB_PAGE
> > +	update_stat(vb, idx++, VIRTIO_BALLOON_S_HTLB_PGALLOC,
> > +		    events[HTLB_BUDDY_PGALLOC]);
> > +	update_stat(vb, idx++, VIRTIO_BALLOON_S_HTLB_PGFAIL,
> > +		    events[HTLB_BUDDY_PGALLOC_FAIL]);
> > +#endif
> >   #endif
> >   	update_stat(vb, idx++, VIRTIO_BALLOON_S_MEMFREE,
> >   				pages_to_bytes(i.freeram));
> > diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
> > index 4e8b830..e3e8071 100644
> > --- a/include/uapi/linux/virtio_balloon.h
> > +++ b/include/uapi/linux/virtio_balloon.h
> > @@ -53,7 +53,9 @@ struct virtio_balloon_config {
> >   #define VIRTIO_BALLOON_S_MEMTOT   5   /* Total amount of memory */
> >   #define VIRTIO_BALLOON_S_AVAIL    6   /* Available memory as in /proc */
> >   #define VIRTIO_BALLOON_S_CACHES   7   /* Disk caches */
> > -#define VIRTIO_BALLOON_S_NR       8
> > +#define VIRTIO_BALLOON_S_HTLB_PGALLOC  8  /* Number of htlb pgalloc successes */
> > +#define VIRTIO_BALLOON_S_HTLB_PGFAIL   9  /* Number of htlb pgalloc failures */
> > +#define VIRTIO_BALLOON_S_NR       10
>
> Can you clarify the comments pls? Eschew abbreviation.

Sure. How about the following instead? Hoping it makes things clearer, 
without going over the 80 character limit ;)

#define VIRTIO_BALLOON_S_HTLB_PGALLOC  8  /* Hugetlb page allocations */
#define VIRTIO_BALLOON_S_HTLB_PGFAIL   9  /* Hugetlb page allocation 
failures */

If this is better, I'll send out a v2.

Thanks,
Jon

> >   
> >   /*
> >    * Memory statistics structure.
> > --
> > 1.8.3.1