TCP Reassembly Issues

[kerbzo]

Hi,

this patch works for me, also.
Reass counter now does not increase ( tcpreass:                40,
1680,      21,     399,  572562,   0,   0 ) and a severe network
performance issue of netatalk and afpd, used as a "Time Capsule"
server for mac os x,  seems now disappeared.
Really thank you,

best regards,

On Sat, Nov 26, 2011 at 6:23 AM, Lawrence Stewart <lstewart at freebsd.org> wrote:
> On 11/25/11 13:01, Lawrence Stewart wrote:
>>
>> On 11/24/11 18:02, Kris Bauer wrote:
>>>
>>> Hello,
>>>
>>> I am currently experiencing an issue with FreeBSD 9.0-RC2 r227852
>>> where the
>>> net.inet.tcp.reass.curesegments value is constantly increasing (and not
>>> descreasing when there is nominal traffic with the box). It is causing
>>> tcp
>>> slowdowns as described with kern/155407:
>>>
>>> Exhausted net.inet.tcp.reass.maxsegments block recovering tcp session
>>> (for
>>> this socket and any other socket waiting for retransmited packets). After
>>> exhausted net.inet.tcp.reass.maxsegments allocation new entry in
>>> tcp_reass
>>> failed (for this socket and any other socket waiting for retransmited
>>> packets).
>>>
>>> I have increased the reass.maxsegments value to 16384 to temporarily
>>> avoid
>>> the problem, but the cursegments number keeps rising and it seems it will
>>> occur again.
>>>
>>> Is this an issue that anyone else has seen? I can provide more
>>> information
>>> if need be.
>>
>> Thanks Kris, Raul and Stefan for the reports, I'll look into this.
>
> I think I've got it - a stupid 1 line logic bug. My apologies for missing it
> when I reviewed the patch which introduced the bug (patch was committed to
> head as r226113, MFCed to stable/9 as r226228).
>
> Due to some miscommunication, the initial patch was committed to and MFCed
> from head much later than it should have been in the 9.0 release cycle and
> instead of being included in the BETAs, didn't make it in until 9.0-RC1 I
> believe i.e. only RC1 and RC2 should be experiencing the issue.
>
> Could those who have reported the bug and are able to recompile their kernel
> to test a patch please try the following and report back to the list:
>
> http://people.freebsd.org/~lstewart/patches/misctcp/tcp_reass_plugzoneleak_10.x.r227986.patch
>
> The patch is against head r227986 but will apply and work correctly for 9.0
> as well.
>
> Cheers,
> Lawrence
>