Re: [PATCH 1/8] Scaling msgmni to the amount of lowmem

[Nadia Derbey <Nadia.Derbey@bull.net>]

Tony Luck wrote:
> On Mon, Feb 11, 2008 at 7:16 AM,  <Nadia.Derbey@bull.net> wrote:
> 
>> Index: linux-2.6.24-mm1/ipc/msg.c
>> ===================================================================
>> --- linux-2.6.24-mm1.orig/ipc/msg.c     2008-02-07 15:02:29.000000000 +0100
>> +++ linux-2.6.24-mm1/ipc/msg.c  2008-02-07 15:24:19.000000000 +0100
> 
> ...
> 
>> +out_callback:
>> +
>> +       printk(KERN_INFO "msgmni has been set to %d for ipc namespace %p\n",
>> +               ns->msg_ctlmni, ns);
>> +}
> 
> 
> This patch has now made its way to mainline.  I can see how this printk
> was really useful to you while developing this patch. But does it add
> much value in a production system? It just looks like another piece of
> clutter on the console to my uncontainerized eyes.
> 
> -Tony
> 
> 


Well, this printk had been suggested by somebody (sorry I don't remember 
who) when I first submitted the patch. Actually I think it might be 
useful for a sysadmin to be aware of a change in the msgmni value: we 
have the message not only at boot time, but also each time msgmni is 
recomputed because of a change in the amount of memory.
Also, at boot time, I think it's interesting to have the actual msgmni 
value: it used to unconditionally be set to 16. Some applications that 
used to need an initialization script setting msgmni to a higher value 
might not need that script anymore, since the new value might fit their 
needs.

Regards,
Nadia