From: Patrick McHardy <kaber@trash.net>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>,
Juliusz Chroboczek <Juliusz.Chroboczek@pps.jussieu.fr>,
"John W. Linville" <linville@tuxdriver.com>,
Stephen Hemminger <shemminger@vyatta.com>,
netdev <netdev@vger.kernel.org>, Andi Kleen <andi@firstfloor.org>
Subject: Re: [PATCH net-next-2.6 v3] net_sched: SFB flow scheduler
Date: Wed, 23 Feb 2011 17:58:04 +0100 [thread overview]
Message-ID: <4D653C9C.8010205@trash.net> (raw)
In-Reply-To: <1298479711.3301.373.camel@edumazet-laptop>
Am 23.02.2011 17:48, schrieb Eric Dumazet:
> Le mercredi 23 février 2011 à 17:24 +0100, Patrick McHardy a écrit :
>
>> This needs to be a per-skb property, otherwise you could have the
>> situation:
>>
>> - enqueue skb, double_buffering=0, increment buffer 0
>> - enable double buffering
>> - swap buffers
>> - dequeue same skb, decrement buffer 1
>>
>> after which the qlen values of buffer 1 will be incorrect.
>>
>
> Normally its OK, because we bzero() the zone, and the "decrement" is
> 0-bounded.
Yeah, but we might decrement buckets of different flows which
are non-zero. Probably not too bad, but still not correct.
> I had this idea (of storing two bits per skb), but :
>
> - It means that swap_buffer() should not touch (bzero) the 'old' bins
Yes, it means we have to properly decrement the old buffer
until all bins reached zero.
> - Since hash perturbator is changed, we have to store the two hash
> values per skb (instead of one u32 / classid).
Indeed.
next prev parent reply other threads:[~2011-02-23 16:58 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20110221160306.GA9650@tuxdriver.com>
[not found] ` <1298308283.2849.5.camel@edumazet-laptop>
[not found] ` <1298390536.2861.9.camel@edumazet-laptop>
2011-02-23 15:14 ` [PATCH net-next-2.6 v3] net_sched: SFB flow scheduler Eric Dumazet
2011-02-23 15:43 ` Stephen Hemminger
2011-02-23 16:13 ` Eric Dumazet
2011-02-23 16:20 ` Patrick McHardy
2011-02-23 16:24 ` Patrick McHardy
2011-02-23 16:48 ` Eric Dumazet
2011-02-23 16:58 ` Patrick McHardy [this message]
2011-02-23 17:16 ` Eric Dumazet
2011-02-23 17:05 ` [PATCH] net_sched: long word align struct qdisc_skb_cb data Eric Dumazet
2011-02-23 17:30 ` Stephen Hemminger
2011-02-23 22:17 ` David Miller
2011-02-23 20:56 ` [PATCH net-next-2.6 v4] net_sched: SFB flow scheduler Eric Dumazet
2011-02-23 21:11 ` Stephen Hemminger
2011-02-23 21:28 ` Eric Dumazet
2011-02-23 21:30 ` David Miller
2011-02-23 22:06 ` David Miller
2011-02-24 5:40 ` Eric Dumazet
2011-02-24 6:51 ` Stephen Hemminger
2011-02-24 7:14 ` Eric Dumazet
2011-02-24 7:18 ` Eric Dumazet
2011-03-24 17:44 ` [PATCH iproute2] tc : " Eric Dumazet
2011-03-24 21:59 ` Stephen Hemminger
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