Re: Interpreting perf stat on netperf and netserver

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 ?