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From: Saeed Mahameed <saeedm@mellanox.com>
To: "eric.dumazet@gmail.com" <eric.dumazet@gmail.com>,
	"davem@davemloft.net" <davem@davemloft.net>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [RFC net-next 1/2] net: net-porcfs: Reduce rcu lock critical section
Date: Thu, 12 Apr 2018 19:12:27 +0000	[thread overview]
Message-ID: <1523560344.3587.40.camel@mellanox.com> (raw)
In-Reply-To: <3e0f5494-3d5c-06e8-a5b2-12b735390629@gmail.com>

On Wed, 2018-04-11 at 19:59 -0700, Eric Dumazet wrote:
> 
> On 04/11/2018 04:47 PM, Saeed Mahameed wrote:
> > 
> > Well if we allow devices to access HW counters via FW command
> > interfaces in ndo_get_stats and by testing mlx5 where we query up
> > to 5
> > hw registers, it could take 100us, still this is way smaller than
> > 10sec
> >  :) and it is really a nice rate to fetch HW stats on demand.
> 
> If hardware stats are slower than software ones, maybe it is time to
> use software stats,
> instead of changing the whole stack ?
> 

We already have SW stats for [rx/tx]_[packets/bytes] but for
[rx/tx]_[error/drop] etc .. they can only be grabbed from HW.

We don't want to report only partial counters to get_stats ndo just to
avoid sleeping.

> There are very few devices drivers having issues like that.
> 


  reply	other threads:[~2018-04-12 19:12 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-10 17:08 [RFC net-next 1/2] net: net-porcfs: Reduce rcu lock critical section Saeed Mahameed
2018-04-10 17:08 ` [RFC net-next 2/2] net: net-sysfs: Reduce netstat_show read_lock " Saeed Mahameed
2018-04-10 17:17   ` David Miller
2018-04-10 17:16 ` [RFC net-next 1/2] net: net-porcfs: Reduce rcu lock " David Miller
2018-04-10 20:35   ` Eric Dumazet
2018-04-11 18:59     ` Saeed Mahameed
2018-04-11 22:30       ` Eric Dumazet
2018-04-11 23:47         ` Saeed Mahameed
2018-04-12  2:59           ` Eric Dumazet
2018-04-12 19:12             ` Saeed Mahameed [this message]
2018-04-16 20:50               ` Saeed Mahameed
2018-04-16 21:07                 ` Eric Dumazet

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