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From: Rick Jones <rick.jones2@hpe.com>
To: Alexander Duyck <alexander.duyck@gmail.com>,
	Eric Dumazet <eric.dumazet@gmail.com>
Cc: netdev <netdev@vger.kernel.org>, Alexander Duyck <aduyck@mirantis.com>
Subject: Re: [RFC] net: remove busylock
Date: Thu, 19 May 2016 11:41:39 -0700	[thread overview]
Message-ID: <573E08E3.3020200@hpe.com> (raw)
In-Reply-To: <CAKgT0UfBxW=KpqJux+tjyNpHQUHhZ5Laiqnt5FPs=jpkBJWrHA@mail.gmail.com>

On 05/19/2016 11:03 AM, Alexander Duyck wrote:
> On Thu, May 19, 2016 at 10:08 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
>> With HTB qdisc, here are the numbers for 200 concurrent TCP_RR, on a host with 48 hyperthreads.
...
>>
>> That would be a 8 % increase.
>
> The main point of the busy lock is to deal with the bulk throughput
> case, not the latency case which would be relatively well behaved.
> The problem wasn't really related to lock bouncing slowing things
> down.  It was the fairness between the threads that was killing us
> because the dequeue needs to have priority.

Quibbledrift... While the origins of the netperf TCP_RR test center on 
measuring latency, I'm not sure I'd call 200 of them running 
concurrently a latency test.  Indeed it may be neither fish nor fowl, 
but it will certainly be exercising the basic packet send/receive path 
rather fully and is likely a reasonable proxy for aggregate small packet 
performance.

happy benchmarking,

rick jones

  reply	other threads:[~2016-05-19 18:41 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-19 17:08 [RFC] net: remove busylock Eric Dumazet
2016-05-19 18:03 ` Alexander Duyck
2016-05-19 18:41   ` Rick Jones [this message]
2016-05-19 18:56   ` Eric Dumazet
2016-05-19 19:35     ` Eric Dumazet
2016-05-19 20:39       ` Alexander Duyck
2016-05-20  4:49         ` John Fastabend
2016-05-20  4:56           ` Eric Dumazet
2016-05-20  7:29   ` Jesper Dangaard Brouer
2016-05-20 13:11     ` Eric Dumazet
2016-05-20 13:47       ` Eric Dumazet
2016-05-20 14:16         ` Eric Dumazet
2016-05-20 17:49           ` Jesper Dangaard Brouer
2016-05-20 21:32             ` Eric Dumazet
2016-05-23  9:50               ` Jesper Dangaard Brouer
2016-05-23 21:24                 ` [PATCH net] net_sched: avoid too many hrtimer_start() calls Eric Dumazet
2016-05-24 21:49                   ` David Miller
2016-05-24 13:50             ` [RFC] net: remove busylock David Laight
2016-05-24 14:37               ` Eric Dumazet
2016-05-20 16:01       ` John Fastabend
2016-05-19 18:12 ` David Miller
2016-05-19 18:44   ` Eric Dumazet

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