Messages in this thread | | | Date | Fri, 23 Jun 2006 13:14:54 -0700 (PDT) | From | Danial Thom <> | Subject | Re: Measuring tools - top and interrupts |
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--- Mike Galbraith <efault@gmx.de> wrote:
> On Thu, 2006-06-22 at 16:37 -0700, Danial Thom > wrote: > > I'm sorry, but you're being an idiot if you > think > > that 16K interrupts per second and forwarding > 75K > > pps generate no cpu load. Its just that > simple. > > It also means that you've never profiled a > kernel > > because you don't understand where the loads > are > > generated. You've probably been on too many > lists > > with too many people who have no idea what > > they're talking about. > > (what horrid manners) > > Hm. You may be right about the load average > calculation being broken. > > Below is a 100 second profile sample of my 3GHz > P4 handling 15K > interrupts per second while receiving a flood > ping. My interpretation > is that tools should be showing ~10% cpu load > rather than zero. Am I'm > misinterpreting it? > > 97574 total > 0.0258 > 89549 default_idle > 1017.6023 > 1734 ioread16 > 36.8936 > 1138 ioread8 > 24.7391 > 974 rhine_start_tx > 1.3994 > 534 __do_softirq > 3.8417 > 331 handle_IRQ_event > 3.2772 > 223 rhine_interrupt > 0.0739 > 222 memset > 7.9286 > 194 nf_iterate > 1.5520 > 140 local_bh_enable > 1.0769 > 99 __kmalloc > 1.0532 > 92 net_rx_action > 0.2000 > 85 kfree > 0.9884 > 82 skb_release_data > 0.6406 > 77 csum_partial_copy_generic > 0.3105 > 73 ip_push_pending_frames > 0.0681 > 71 __alloc_skb > 0.2898 > 69 kmem_cache_free > 1.3529 > 66 kmem_cache_alloc > 1.3750 > 62 csum_partial > 0.2153 > 61 rt_hash_code > 0.4959 > 61 ip_append_data > 0.0253 > 60 netif_receive_skb > 0.0516 > 58 ip_rcv > 0.0471 > 58 ip_local_deliver > 0.0854 > 58 eth_type_trans > 0.2489 > 55 ip_output > 0.0957 > 52 icmp_reply > 0.1187 > Thats a pretty crappy controller you have in with that shiny P4...
I'm not sure that they want the tools to work. They'll just call you a troll and go on developing unnecessary things like NAPI because they're still using controllers designed by DEC (remember them?) back in the stone ages.
Yet I regularly encounter people using cheap NICs with expensive cpus on network-intensive applications. But you'd think one or two people would have a clue.
DT
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