From: Stephen Hemminger <stephen@networkplumber.org>
To: Yidong Ren <Yidong.Ren@microsoft.com>
Cc: Yidong Ren <yidren@linuxonhyperv.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Haiyang Zhang <haiyangz@microsoft.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"devel@linuxdriverproject.org" <devel@linuxdriverproject.org>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH v2] hv_netvsc: Add per-cpu ethtool stats for netvsc
Date: Wed, 13 Jun 2018 15:18:54 -0700 [thread overview]
Message-ID: <20180613151854.25be8b33@xeon-e3> (raw)
In-Reply-To: <SN6PR2101MB11353820325BBF4712076573847E0@SN6PR2101MB1135.namprd21.prod.outlook.com>
On Wed, 13 Jun 2018 22:03:34 +0000
Yidong Ren <Yidong.Ren@microsoft.com> wrote:
> > From: devel <driverdev-devel-bounces@linuxdriverproject.org> On Behalf
> > Of Stephen Hemminger
> > > +/* statistics per queue (rx/tx packets/bytes) */ #define
> > > +NETVSC_PCPU_STATS_LEN (num_present_cpus() *
> > ARRAY_SIZE(pcpu_stats))
> >
> > Even though Hyper-V/Azure does not support hot plug cpu's it might be
> > better to num_cpu_possible to avoid any possible future surprises.
>
> That will create a very long output (num_cpu_possible = 128 on my machine) for ethtool,
> While doesn't provide additional info.
> num_present_cpus() would cause problem only if someone removed cpu
> between netvsc_get_sset_count() and netvsc_get_strings() and netvsc_get_ethtool_stats().
>
> An alternative way could be: Check all stats, and only output if not zero.
> This need to be done in two pass. First pass to get the correct count, second pass to print the number.
> Is there an elegant way to do this?
Ok, but there is a race between getting names and getting statistics.
If a cpu was added/removed then statistics would not match.
next prev parent reply other threads:[~2018-06-13 22:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-13 19:36 [PATCH v2] hv_netvsc: Add per-cpu ethtool stats for netvsc Yidong Ren
2018-06-13 19:36 ` Yidong Ren
2018-06-13 20:57 ` Eric Dumazet
2018-06-13 20:57 ` Eric Dumazet
2018-06-13 21:07 ` Yidong Ren
2018-06-13 21:48 ` Stephen Hemminger
2018-06-13 22:03 ` Yidong Ren
2018-06-13 22:18 ` Stephen Hemminger [this message]
2018-07-24 1:26 ` [PATCH v3] " Yidong Ren
2018-07-24 1:26 ` Yidong Ren
2018-07-24 1:42 ` Yidong Ren
2018-07-24 11:00 ` Vitaly Kuznetsov
2018-07-24 11:00 ` Vitaly Kuznetsov
2018-07-25 22:54 ` Yidong Ren
2018-07-25 22:54 ` Yidong Ren
2018-07-30 17:09 ` [PATCH v4 net-next] " Yidong Ren
2018-07-30 17:34 ` Stephen Hemminger
2018-07-30 19:34 ` David Miller
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