Re: [TCP bug, regression] stuck distcc connections in latest -git

David Miller
2008-07-24T09:30:03Z

From: Ingo Molnar <mingo@elte.hu>
Date: Thu, 24 Jul 2008 11:25:18 +0200

> ok, i've booted the latest kernel on dione and the builds are running on
> it now. It's using these settings currently:
>
> # cat /proc/sys/net/ipv4/tcp_syncookies
> 0
> # cat /proc/sys/net/ipv4/tcp_sack
> 1
>
> Just to make sure i have the right test-plan: assuming this
> suspected-good kernel is trouble-free for say 48 hours, i should be able
> to switch back to the suspected-broken variant, by doing:
>
> echo 1 > /proc/sys/net/ipv4/tcp_syncookies
>
> without rebooting the kernel, right? And then if the bug comes back
> again we've nailed it down to the area you suspect, correct?

You don't need the explicit tcp_sack=1, it's going to be '1' by
default.

Simply switching syncookies on and off will turn both SACK and
timestamps off when running the dist kernel.