On Sun, 18 Oct 2020 00:35:59 +0300 Vladimir Oltean wrote:
> DSA needs to push a header onto every packet on TX, and this might cause
> reallocation under certain scenarios, which might affect, for example,
> performance.
>
> But reallocated packets are not standardized in struct pcpu_sw_netstats,
> struct net_device_stats or anywhere else, it seems, so we need to roll
> our own extra netdevice statistics and expose them to ethtool.
>
> Signed-off-by: Vladimir Oltean <[email protected]>
Could you consider adding "driver" stats under RTM_GETSTATS,
or a similar new structured interface over ethtool?
Looks like the statistic in question has pretty clear semantics,
and may be more broadly useful.
> +/* Driver statistics, other than those in struct rtnl_link_stats64.
> + * These are collected per-CPU and aggregated by ethtool.
> + */
> +struct dsa_slave_stats {
> + __u64 tx_reallocs;
s/__u/u/
> + struct u64_stats_sync syncp;
> +} __aligned(1 * sizeof(u64));
Why aligned to u64? Compiler should pick a reasonable alignment here
by itself.
