freebsd stable - Dec 2007 - 4.x Collecting pv entries Suggest increasing PMAP_SHPGPERPROC,

Hello List,

I know FreeBSD 4.x is old..., but we are using on a production system 
with postgres and apache. The above message
is appearing periodically. I googled for the message but found no 
recommendation for adjusting it.

Any suggestions.

Thanks,
Steve

-- 

"They that give up essential liberty to obtain temporary safety, 
deserve neither liberty nor safety."  (Ben Franklin)

"The course of history shows that as a government grows, liberty 
decreases."  (Thomas Jefferson)

> I know FreeBSD 4.x is old..., but we are using on a production system
> with postgres and apache. The above message
> is appearing periodically. I googled for the message but found no
> recommendation for adjusting it.
Is the sysctl kern.vm.pmap.shpgperproc available on 4.x? This can be
configured in /boot/loader.conf.

-- 
regards
Claus

When lenity and cruelty play for a kingdom,
the gentlest gamester is the soonest winner.

Shakespeare

Claus Guttesen wrote:
>>I know FreeBSD 4.x is old..., but we are using on a production system
>>with postgres and apache. The above message
>>is appearing periodically. I googled for the message but found no
>>recommendation for adjusting it.
>>    
>>
>
>Is the sysctl kern.vm.pmap.shpgperproc available on 4.x? This can be
>configured in /boot/loader.conf.
>
>  
>
Hi Claus,

It does not appear to be available via a sysctl in 4.x.

Thanks,
Steve

-- 

"They that give up essential liberty to obtain temporary safety, 
deserve neither liberty nor safety."  (Ben Franklin)

"The course of history shows that as a government grows, liberty 
decreases."  (Thomas Jefferson)

Hi Steve,

Stephen Clark wrote:
> Uwe Doering wrote:
>> [...]
>> But you can put that option into the kernel config file:
>>
>>   options PMAP_SHPGPERPROC=...
>>
>> and build a new kernel with it.
> 
> You are correct. My question is more how much should I increase it. The 
> current default in the 4.x LINT file
> is "options PMAP_SHPGPERPROC=201" should I double it? Increase it
by 50
> to 251? Should it be a prime number?
> I am just asking for information.
The settings in the LINT file are not necessarily the defaults, rather 
mere examples.  The default value for PMAP_SHPGPERPROC is 200 (defined 
in the source file /usr/src/sys/i386/i386/pmap.c).  I would recommend to 
increase it by 100 until the messages stop.  We use 300 on our servers, 
for instance.

Regards,

    Uwe
-- 
Uwe Doering         |  EscapeBox - Managed On-Demand UNIX Servers
gemini@geminix.org  |  http://www.escapebox.net

Stephen Clark wrote:
> Claus Guttesen wrote:
>> Stephen Clark wrote:
>>> I know FreeBSD 4.x is old..., but we are using on a production
system
>>> with postgres and apache. The above message
>>> is appearing periodically. I googled for the message but found no
>>> recommendation for adjusting it.
>>
>> Is the sysctl kern.vm.pmap.shpgperproc available on 4.x? This can be
>> configured in /boot/loader.conf.
> 
> It does not appear to be available via a sysctl in 4.x.
But you can put that option into the kernel config file:

   options PMAP_SHPGPERPROC=...

and build a new kernel with it.

Regards,

    Uwe
-- 
Uwe Doering         |  EscapeBox - Managed On-Demand UNIX Servers
gemini@geminix.org  |  http://www.escapebox.net

> >> But you can put that option into the kernel config file:
> >>
> >>   options PMAP_SHPGPERPROC=...
> >>
> >> and build a new kernel with it.
> >
> > You are correct. My question is more how much should I increase it.
The
> > current default in the 4.x LINT file
> > is "options PMAP_SHPGPERPROC=201" should I double it?
Increase it by 50
> > to 251? Should it be a prime number?
> > I am just asking for information.
>
> The settings in the LINT file are not necessarily the defaults, rather
> mere examples.  The default value for PMAP_SHPGPERPROC is 200 (defined
> in the source file /usr/src/sys/i386/i386/pmap.c).  I would recommend to
> increase it by 100 until the messages stop.  We use 300 on our servers,
> for instance.
I do recall I had the same message on a 5.x-server (running
postgresql-server I think, some years ago now :-) ) once in a while. I
think I raised it twice to 400. I remember that the recommendation was
not to raise it too high in order not to make the kernel panic during
boot.

-- 
regards
Claus

When lenity and cruelty play for a kingdom,
the gentlest gamester is the soonest winner.

Shakespeare

Uwe Doering wrote:
> Hi Steve,
>
> Stephen Clark wrote:
>
>> Uwe Doering wrote:
>>
>>> [...]
>>> But you can put that option into the kernel config file:
>>>
>>>   options PMAP_SHPGPERPROC=...
>>>
>>> and build a new kernel with it.
>>
>>
>> You are correct. My question is more how much should I increase it. 
>> The current default in the 4.x LINT file
>> is "options PMAP_SHPGPERPROC=201" should I double it?
Increase it by
>> 50 to 251? Should it be a prime number?
>> I am just asking for information.
>
>
> The settings in the LINT file are not necessarily the defaults, rather 
> mere examples.  The default value for PMAP_SHPGPERPROC is 200 (defined 
> in the source file /usr/src/sys/i386/i386/pmap.c).  I would recommend 
> to increase it by 100 until the messages stop.  We use 300 on our 
> servers, for instance.
>
> Regards,
>
>    Uwe
Thanks a lot for the response. I have only seen the message one time, I 
have 1 gb of memory with dual xeons, so
I was thinking first I would bump it to 251.


Regards,
Steve

-- 

"They that give up essential liberty to obtain temporary safety, 
deserve neither liberty nor safety."  (Ben Franklin)

"The course of history shows that as a government grows, liberty 
decreases."  (Thomas Jefferson)