Re: [net-next PATCH] ixgbe: add counter for times rx pages gets allocated, not recycled

On Fri, 2017-09-01 at 12:54 +0200, Jesper Dangaard Brouer wrote:

The ixgbe driver have page recycle scheme based around the RX-ring
queue, where a RX page is shared between two packets. Based on the
refcnt, the driver can determine if the RX-page is currently only
used
by a single packet, if so it can then directly refill/recycle the
RX-slot by with the opposite "side" of the page.

While this is a clever trick, it is hard to determine when this
recycling is successful and when it fails.  Adding a counter, which
is
available via ethtool --statistics as 'alloc_rx_page'.  Which counts
the number of times the recycle fails and the real page allocator is
invoked.  When interpreting the stats, do remember that every alloc
will serve two packets.

The counter is collected per rx_ring, but is summed and ethtool
exported as 'alloc_rx_page'.  It would be relevant to know what
rx_ring that cannot keep up, but that can be exported later if
someone experience a need for this.

Signed-off-by: Jesper Dangaard Brouer <redacted>

Since Alex has a suggested change for this patch, when you resubmit v2,
can you make sure you CC intel-wired-lan mailing list, so that my
patchwork project picks up this patch?  Thanks in advance Jesper.