2004-03-11 12:33:49

by Gerald Krafft

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Subject: hanging in wait_for_tcp_memory

I have some database processes (Interbase V6) that occasionally seem to
hang. Using ps or top I found that they are waiting in
wait_for_tcp_memory. What exactly does wait_for_tcp_memory do and under
which circumstances does this function block?
I'm using Red Hat Linux 7.2, kernel version 2.4.7-10smp on a dual
processor machine. Were there any known problems with
wait_for_tcp_memory in that kernel version that might have been fixed in
later versions?

Thanks
Gerald



2004-03-11 12:42:35

by Arjan van de Ven

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Subject: Re: hanging in wait_for_tcp_memory

On Thu, 2004-03-11 at 13:33, Gerald Krafft wrote:
> I have some database processes (Interbase V6) that occasionally seem to
> hang. Using ps or top I found that they are waiting in
> wait_for_tcp_memory. What exactly does wait_for_tcp_memory do and under
> which circumstances does this function block?
> I'm using Red Hat Linux 7.2, kernel version 2.4.7-10smp on a dual
> processor machine. Were there any known problems with
> wait_for_tcp_memory in that kernel version that might have been fixed in
> later versions

2.4.7-10 had a really really bad vm, so we replaced it with another
kernel the day of 7.2 release (which also was needed for security
fixes). Sounds like you need to apply a bunch of (security) errata to
get your system performing better...


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2004-03-11 14:57:32

by Gerald Krafft

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Subject: Re: hanging in wait_for_tcp_memory

Thanks, so I will have to upgrade my system to a later kernel. It would
still be nice if somebody could explain what this kernal function does,
when it is usually called and under which circumstances it might block.

Gerald

Arjan van de Ven wrote:

> On Thu, 2004-03-11 at 13:33, Gerald Krafft wrote:
>
>>I have some database processes (Interbase V6) that occasionally seem to
>>hang. Using ps or top I found that they are waiting in
>>wait_for_tcp_memory. What exactly does wait_for_tcp_memory do and under
>>which circumstances does this function block?
>>I'm using Red Hat Linux 7.2, kernel version 2.4.7-10smp on a dual
>>processor machine. Were there any known problems with
>>wait_for_tcp_memory in that kernel version that might have been fixed in
>>later versions
>
>
> 2.4.7-10 had a really really bad vm, so we replaced it with another
> kernel the day of 7.2 release (which also was needed for security
> fixes). Sounds like you need to apply a bunch of (security) errata to
> get your system performing better...