----- Original Message -----
From: "Rik van Riel" <riel@conectiva.com.br>
To: "Vincent Sweeney" <v.sweeney@barrysworld.com>
Cc: "Alan Cox" <alan@lxorguk.ukuu.org.uk>; <linux-kernel@vger.kernel.org>
Sent: Monday, January 28, 2002 7:40 PM
Subject: Re: PROBLEM: high system usage / poor SMP network performance
> On Mon, 28 Jan 2002, Vincent Sweeney wrote:
>
> > > > CPU0 states: 27.2% user, 62.4% system, 0.0% nice, 9.2% idle
> > > > CPU1 states: 28.4% user, 62.3% system, 0.0% nice, 8.1% idle
> > >
> > > The important bit here is ^^^^^^^^ that one. Something is causing
> > > horrendous lock contention it appears.
> >
> > I've switched a server over to the default eepro100 driver as supplied
> > in 2.4.17 (compiled as a module). This is tonights snapshot with about
> > 10% higher user count than above (2200 connections per ircd)
>
> Hummm ... poll() / select() ? ;)
>
> > I will try the profiling tomorrow
>
> readprofile | sort -n | tail -20
>
> kind regards,
>
> Rik
Right then, here is the results from today so far (snapshot taken with 2000
users per ircd). Kernel profiling enabled with the eepro100 driver compiled
statically.
--- > readprofile -r ; sleep 60; readprofile | sort -n | tail -3011 tcp_rcv_established 0.0055 12 do_softirq 0.0536 12 nf_hook_slow 0.0291 13 __free_pages_ok 0.0256 13 kmalloc 0.0378 13 rmqueue 0.0301 13 tcp_ack 0.0159 14 __kfree_skb 0.0455 14 tcp_v4_rcv 0.0084 15 __ip_conntrack_find 0.0441 16 handle_IRQ_event 0.1290 16 tcp_packet 0.0351 17 speedo_rx 0.0227 17 speedo_start_xmit 0.0346 18 ip_route_input 0.0484 23 speedo_interrupt 0.0301 30 ipt_do_table 0.0284 30 tcp_sendmsg 0.0065 116 __pollwait 0.7838 140 poll_freewait 1.7500 170 sys_poll 0.1897 269 do_pollfd 1.4944 462 remove_wait_queue 12.8333 474 add_wait_queue 9.1154 782 fput 3.3707 1216 default_idle 23.3846 1334 fget 16.6750 1347 sock_poll 33.6750 2408 tcp_poll 6.9195 9366 total 0.0094
> top
4:30pm up 2:57, 2 users, load average: 0.76, 0.85, 0.82 36 processes: 33 sleeping, 3 running, 0 zombie, 0 stopped CPU0 states: 21.4% user, 68.1% system, 0.0% nice, 9.3% idle CPU1 states: 23.4% user, 67.1% system, 0.0% nice, 8.3% idle Mem: 382916K av, 191276K used, 191640K free, 0K shrd, 1444K buff Swap: 379416K av, 0K used, 379416K free 23188K cached
PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND 613 ircd 16 0 67140 65M 660 R 89.6 17.5 102:00 ircd 607 ircd 16 0 64868 63M 656 S 88.7 16.9 98:50 ircd
---
So with my little knowledge of what this means I would say this is purely down to poll(), but surely even with 4000 connections to the box that shouldn't stretch a dual P3-800 box as much as it does?
Vince.
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This archive was generated by hypermail 2b29 : Thu Jan 31 2002 - 21:01:04 EST