Re: Linux 2.6.25-rc6: WARNING: at net/ipv4/tcp_input.c:2510

From: Ilpo Järvinen
Date: Fri Apr 04 2008 - 15:18:40 EST


On Fri, 4 Apr 2008, Georgi Chorbadzhiyski wrote:

> Around 04/03/08 13:17, Ilpo Järvinen scribbled:
> > On Thu, 27 Mar 2008, Georgi Chorbadzhiyski wrote:
> >
> >> A week ago I updated one of my servers to 2.6.25-rc6 and today looking
> >> through logs I've found these:
> >>
> >> [380219.823434] ------------[ cut here ]------------
> >> [380219.823450] WARNING: at net/ipv4/tcp_input.c:2510 tcp_ack+0xc7e/0x177d()
> >
> > Is this reproducable for you? If yes, is it possible for you to run
>
> Not in the moment.
>
> I'm not getting such errors in the log since my last report. Today I'll
> update to latest -git and will restart the server.

Yeah, the reason why these still happen is that they are quite hard to
hit.

> The machine that gave me this error is a http and ftp server handling not
> very busy distro mirror (if this can give you any clues).
>
> > processing expensive verification of TCP state (validates TCP write queue
> > invariants multiple times per ACK by scanning through the write queue) on
> > such machine?
>
> How to run such a thing, can you give me some pointers?

I sent the patch recently to netdev/lkml:

http://marc.info/?l=linux-netdev&m=120733529216457&w=2

But it's very expensive in processing wise so it might not be wise to put
it in if performance is important for you.


--
i.