[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAL8zT=hr6vf3tUFaxH_Qk8E3HPd6=WNjrHeMLph2e54sagu37w@mail.gmail.com>
Date: Thu, 19 Jan 2012 11:26:34 +0100
From: Jean-Michel Hautbois <jhautbois@...il.com>
To: Eric Dumazet <eric.dumazet@...il.com>
Cc: netdev@...r.kernel.org
Subject: Re: Interpreting perf stat on netperf and netserver
2012/1/19 Eric Dumazet <eric.dumazet@...il.com>:
> Le mercredi 18 janvier 2012 à 12:33 +0100, Jean-Michel Hautbois a
> écrit :
>
>> The be2net driver seems to have difficulties woth IRQ affinity also,
>> because it always uses CPU0 even if the affinity is 0-23 !
>> netperf result is quite good, and perf top shows :
>> PerfTop: 689 irqs/sec kernel:99.6% us: 0.3% guest kernel: 0.0%
>> guest us: 0.0% exact: 0.0% [1000Hz cycles], (all, 24 CPUs)
>> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>>
>> 29.28% [kernel] [k] csum_partial
>> 8.46% [kernel] [k] copy_user_generic_string
>> 3.70% [be2net] [k] be_poll_rx
>> 3.08% [be2net] [k] event_handle
>> 2.37% [kernel] [k] irq_entries_start
>> 2.21% [be2net] [k] be_rx_compl_get
>> 1.65% [be2net] [k] be_post_rx_frags
>> 1.64% [kernel] [k] __napi_complete
>> 1.50% [kernel] [k] ip_defrag
>> 1.35% [kernel] [k] put_page
>> 1.34% [kernel] [k] get_page_from_freelist
>> 1.29% [kernel] [k] __netif_receive_skb
>> 1.16% [kernel] [k] __alloc_pages_nodemask
>> 1.14% [kernel] [k] debug_smp_processor_id
>> 1.08% [kernel] [k] add_preempt_count
>> 1.06% [kernel] [k] sub_preempt_count
>> 1.03% [be2net] [k] get_rx_page_info
>> 1.01% [kernel] [k] alloc_pages_current
>>
>> Checksum calculation seems quite complex :).
>
> UDP with fragments... I guess... but cant see this in the perf top
> output ;)
>
> What bandwidth do you get for this cpu load ?
Yes, this was UDP fragmentation :). I had 6800Mbps for a theoretical
limit of 7000Mbps (Flex 10Gbps system).
JM
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists