Re: major network performance difference between 2.4 and 2.6.2-rc2
From: Andrew Morton <hidden>
Date: 2004-02-04 20:56:39
Jim Faulkner [off-list ref] wrote:
I am still experiencing severely degraded network performance under 2.6.2-rc3 and 2.6.2-rc3-mm1.
A kernel profile is needed.
Based on some kernel output, I think this problem may be related to Gerd Knorr's input patches, so I am CCing him on this e-mail.
Sounds unlikely.
Additionally, while large network transfers are going on, both ksoftirqd/0 and events/0 start going crazy, putting a huge load on my system: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3 root 35 19 0 0 0 S 45.9 0.0 0:46.98 ksoftirqd/0 6 root 5 -10 0 0 0 S 43.3 0.0 1:56.63 events/0 12008 dogshu 15 0 4800 2356 3828 S 5.3 0.2 0:05.98 proftpd 12 root 15 0 0 0 0 S 0.3 0.0 0:00.41 pdflush 9778 root 16 0 5888 1724 5516 R 0.3 0.2 0:00.12 sshd the load before that network transfer was 0.01, and the load after the network transfer was 1.45.
Could be a networking problem, but boy that's a lot of CPU time. Please, do this: - Boot with `profile=1' on the kernel command line sudo readprofile -r sudo readprofile -M10 time <whatever command it is that is causing the problem> readprofile -n -v -m /boot/System.map | sort -n +2 | tail -40 | tee ~/log Making very sure that /boot/System.map is the correct map file for the currently-running kernel. Thanks.