From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH net-next] r8169: Add 64bit statistics
Date: Thu, 17 Nov 2011 09:11:56 +0100
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Cc: Stephen Hemminger <stephen.hemminger@vyatta.com>,
	netdev@vger.kernel.org, romieu@fr.zoreil.com,
	nic swsd <nic_swsd@realtek.com>
To: Junchang Wang <junchangwang@gmail.com>
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Le jeudi 17 novembre 2011 =C3=A0 15:46 +0800, Junchang Wang a =C3=A9cri=
t :
> > You dont need per-cpu since Tx is locked by dev->xmit_lock and
> > rx is implicitly single threaded by NAPI.
>=20
> Thanks.
>=20
> >You do need to have
> > two u64_stat_sync entries (one for Tx and one for Rx).
>=20
> You mean Rx and Tx will perform on different cores at one moment.
> So I need a sync for Tx to protect tx_xxx, and another for Rx to
> protect rx_xxx. Is that right?
>=20

Yes, look at sky2.c for a template

drivers/net/ethernet/marvell/sky2.c contains code like that
(different syncp for rx/tx)

TX path:
                        u64_stats_update_begin(&sky2->tx_stats.syncp);
                        ++sky2->tx_stats.packets;
                        sky2->tx_stats.bytes +=3D skb->len;
                        u64_stats_update_end(&sky2->tx_stats.syncp);


RX path:

        u64_stats_update_begin(&sky2->rx_stats.syncp);
        sky2->rx_stats.packets +=3D packets;
        sky2->rx_stats.bytes +=3D bytes;
        u64_stats_update_end(&sky2->rx_stats.syncp);