Re: PROBLEM: high system usage / poor SMP network performance

Vincent Sweeney (v.sweeney@barrysworld.com)
Mon, 28 Jan 2002 19:34:35 -0000


----- Original Message -----
From: "Alan Cox" <alan@lxorguk.ukuu.org.uk>
To: "Vincent Sweeney" <v.sweeney@barrysworld.com>
Cc: <linux-kernel@vger.kernel.org>
Sent: Sunday, January 27, 2002 10:54 PM
Subject: Re: PROBLEM: high system usage / poor SMP network performance

> > 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. Is the e100 driver optimised for
SMP
> yet ? Do you get better numbers if you use the eepro100 driver ?

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)

7:25pm up 5:44, 2 users, load average: 0.85, 1.01, 1.09
38 processes: 33 sleeping, 5 running, 0 zombie, 0 stopped
CPU0 states: 27.3% user, 69.3% system, 0.0% nice, 2.2% idle
CPU1 states: 26.1% user, 71.2% system, 0.0% nice, 2.0% idle
Mem: 385096K av, 232960K used, 152136K free, 0K shrd, 4724K
buff
Swap: 379416K av, 0K used, 379416K free 21780K
cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND
659 ircd 15 0 74976 73M 660 R 96.7 19.4 263:21 ircd
666 ircd 14 0 75004 73M 656 R 95.5 19.4 253:10 ircd

So as you can see the numbers are almost the same, though they were worse at
lower users than the e100 driver (~45% system per cpu at 1000 users per ircd
with eepro100, ~30% with e100).

I will try the profiling tomorrow with the eepro100 driver compiled into the
kernel, I was unable to do the same for the Intel e100 driver today as I
discovered that the Intel driver can currenty only be compiled as a module.

Vince.

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