Gentoo Archives: gentoo-amd64

From: Peter Humphrey <prh@××××××××××.uk>
To: gentoo-amd64@l.g.o
Subject: [gentoo-amd64] Unexpected side effect of GCC 4
Date: Sun, 05 Nov 2006 08:48:19
Message-Id: 200611050845.42865.prh@gotadsl.co.uk
1 I have a firewall between my ADSL modem and my local network (running
2 Gentoo, naturally), and I use it as an rsync server for portage on the
3 network. Specifically, the firewall runs emerge --sync in a cron job every
4 morning before I get up, then I synchronise my laptop and desktop systems
5 from that at my convenience.
6
7 The rsync phase of update over the local network has been extremely slow; I
8 couldn't get traffic flowing faster than about 30 - 40 kBps on average, and
9 the hub showed tremendous numbers of collisions. I did manage to speed it
10 up a bit by changing the /usr/portage partition on the server to reiserfs,
11 but that improvement seemed to go away again. Meanwhile, other traffic over
12 the network went at full speed, about 270 kBps, with only the occasional
13 collision.
14
15 Now that I've finally managed to build a full system using GCC 4.1.1 on the
16 workstation, I find its rsync traffic has leapt to full speed with no
17 collisions to speak of. I'm not complaining, mind, but this is a puzzle. As
18 far as I know I haven't changed anything else - certainly the firewall box
19 has been running continuously throughout.
20
21 The speeds I mention are as shown by gkrellm (a very useful utility). The
22 network drivers are a module on the workstation (tg3) and built-in on the
23 firewall (8139too). The CFLAGS are "-O2 -march=k8 -pipe" on the firewall
24 and the set offered by Duncan recently on the workstation.
25
26 Any ideas, anyone?
27
28 --
29 Rgds
30 Peter
31 --
32 gentoo-amd64@g.o mailing list

Replies

Subject Author
[gentoo-amd64] Re: Unexpected side effect of GCC 4 Duncan <1i5t5.duncan@×××.net>
Re: [gentoo-amd64] Unexpected side effect of GCC 4 Peter Humphrey <prh@××××××××××.uk>