From: Kenny Chang <kchang@athenacr•com>
To: netdev@vger•kernel.org
Subject: Re: Multicast packet loss
Date: Tue, 03 Feb 2009 10:20:13 -0500 [thread overview]
Message-ID: <498860AD.5010702@athenacr.com> (raw)
In-Reply-To: <20090203115502.GB28117@hmsreliant.think-freely.org>
Neil Horman wrote:
> On Mon, Feb 02, 2009 at 11:48:25AM -0500, Kenny Chang wrote:
>
>> Neil Horman wrote:
>>
>>> On Fri, Jan 30, 2009 at 11:41:23PM +0100, Eric Dumazet wrote:
>>>
>>>
>>>> Kenny Chang a écrit :
>>>>
>>>>
>>>>> Ah, sorry, here's the test program attached.
>>>>>
>>>>> We've tried 2.6.28.1, but no, we haven't tried the 2.6.28.2 or the
>>>>> 2.6.29.-rcX.
>>>>>
>>>>> Right now, we are trying to step through the kernel versions until we
>>>>> see where the performance drops significantly. We'll try 2.6.29-rc soon
>>>>> and post the result.
>>>>>
>>>>>
>>>> 2.6.29-rc contains UDP receive improvements (lockless)
>>>>
>>>> Problem is multicast handling was not yet updated, but could be :)
>>>>
>>>>
>>>> I was asking you "cat /proc/interrupts" because I believe you might
>>>> have a problem NIC interrupts being handled by one CPU only (when having problems)
>>>>
>>>>
>>>>
>>> That would be expected (if irqbalance is running), and desireable, since
>>> spreading high volume interrupts like NICS accross multiple cores (or more
>>> specifically multiple L2 caches), is going increase your cache line miss rate
>>> significantly and decrease rx throughput.
>>>
>>> Although you do have a point here, if the system isn't running irqbalance, and
>>> the NICS irq affinity is spread accross multiple L2 caches, that would be a
>>> point of improvement performance-wise.
>>>
>>> Kenny, if you could provide the /proc/interrupts info along with /proc/cpuinfo
>>> and your stats that I asked about earlier, that would be a big help.
>>>
>>> Regards
>>> Neil
>>>
>>>
>>>
>> This is for a working setup.
>>
>>
>
> Are these quad core systems? Or dual core w/ hyperthreading? I ask because in
> your working setup you have 1/2 the number of cpus' and was not sure if you
> removed an entire package of if you just disabled hyperthreading.
>
>
> Neil
>
>
Yeah, these are quad core systems. The 8 cpu system is a dual-processor
quad-core. The other is my desktop, single cpu quad core.
Kenny
next prev parent reply other threads:[~2009-02-03 15:20 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-30 17:49 Multicast packet loss Kenny Chang
2009-01-30 19:04 ` Eric Dumazet
2009-01-30 19:17 ` Denys Fedoryschenko
2009-01-30 20:03 ` Neil Horman
2009-01-30 22:29 ` Kenny Chang
2009-01-30 22:41 ` Eric Dumazet
2009-01-31 16:03 ` Neil Horman
2009-02-02 16:13 ` Kenny Chang
2009-02-02 16:48 ` Kenny Chang
2009-02-03 11:55 ` Neil Horman
2009-02-03 15:20 ` Kenny Chang [this message]
2009-02-04 1:15 ` Neil Horman
2009-02-04 16:07 ` Kenny Chang
2009-02-04 16:46 ` Wesley Chow
2009-02-04 18:11 ` Eric Dumazet
2009-02-05 13:33 ` Neil Horman
2009-02-05 13:46 ` Wesley Chow
2009-02-05 13:29 ` Neil Horman
2009-02-01 12:40 ` Eric Dumazet
2009-02-02 13:45 ` Neil Horman
2009-02-02 16:57 ` Eric Dumazet
2009-02-02 18:22 ` Neil Horman
2009-02-02 19:51 ` Wes Chow
2009-02-02 20:29 ` Eric Dumazet
2009-02-02 21:09 ` Wes Chow
2009-02-02 21:31 ` Eric Dumazet
2009-02-03 17:34 ` Kenny Chang
2009-02-04 1:21 ` Neil Horman
2009-02-26 17:15 ` Kenny Chang
2009-02-28 8:51 ` Eric Dumazet
2009-03-01 17:03 ` Eric Dumazet
2009-03-04 8:16 ` David Miller
2009-03-04 8:36 ` Eric Dumazet
2009-03-07 7:46 ` Eric Dumazet
2009-03-08 16:46 ` Eric Dumazet
2009-03-09 2:49 ` David Miller
2009-03-09 6:36 ` Eric Dumazet
2009-03-13 21:51 ` David Miller
2009-03-13 22:30 ` Eric Dumazet
2009-03-13 22:38 ` David Miller
2009-03-13 22:45 ` Eric Dumazet
2009-03-14 9:03 ` [PATCH] net: reorder fields of struct socket Eric Dumazet
2009-03-16 2:59 ` David Miller
2009-03-16 22:22 ` Multicast packet loss Eric Dumazet
2009-03-17 10:11 ` Peter Zijlstra
2009-03-17 11:08 ` Eric Dumazet
2009-03-17 11:57 ` Peter Zijlstra
2009-03-17 15:00 ` Brian Bloniarz
2009-03-17 15:16 ` Eric Dumazet
2009-03-17 19:39 ` David Stevens
2009-03-17 21:19 ` Eric Dumazet
2009-04-03 19:28 ` Brian Bloniarz
2009-04-05 13:49 ` Eric Dumazet
2009-04-06 21:53 ` Brian Bloniarz
2009-04-06 22:12 ` Brian Bloniarz
2009-04-07 20:08 ` Brian Bloniarz
2009-04-08 8:12 ` Eric Dumazet
2009-03-09 22:56 ` Brian Bloniarz
2009-03-10 5:28 ` Eric Dumazet
2009-03-10 23:22 ` Brian Bloniarz
2009-03-11 3:00 ` Eric Dumazet
2009-03-12 15:47 ` Brian Bloniarz
2009-03-12 16:34 ` Eric Dumazet
2009-02-27 18:40 ` Christoph Lameter
2009-02-27 18:56 ` Eric Dumazet
2009-02-27 19:45 ` Christoph Lameter
2009-02-27 20:12 ` Eric Dumazet
2009-02-27 21:36 ` Eric Dumazet
2009-02-02 13:53 ` Eric Dumazet
-- strict thread matches above, loose matches on Subject: below --
2009-04-05 14:42 bmb
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