Re: [PATCH net-next v5 07/10] forcedeth: implement ndo_get_stats64() API

On Wed, 2011-11-16 at 08:55 -0800, Stephen Hemminger wrote:

On Tue, 15 Nov 2011 21:15:55 -0800
David Decotigny [off-list ref] wrote:

quoted

This commit implements the ndo_get_stats64() API for forcedeth. Since
these stats are being updated from different contexts (process and
timer), this commit adds protection (locking + atomic variables).

Tested:
  - 16-way SMP x86_64 ->
    RX bytes:7244556582 (7.2 GB)  TX bytes:181904254 (181.9 MB)
  - pktgen + loopback: identical rx_bytes/tx_bytes and rx_packets/tx_packets

Rather than adding additional locking why not use a percpu structure
to hold statistics. See loopback, macvlan, veth, xen-netfront.

percpu is stupid for a single-queue driver.

Or realize that the Tx side is single threaded by dev->xmit_lock already
and the Rx side is single threaded by NAPI.

Right.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.