[mvapich-discuss] problem w/MVAPICH in the frames of Gen1

[Mikhail Kuzminsky]

In message from Jimmy Tang <jtang at tchpc.tcd.ie> (Thu, 10 Aug 2006 
19:25:19 +0100):
>Hi Mikhail,
>On Thu, Aug 10, 2006 at 10:02:27PM +0400, Mikhail Kuzminsky wrote:
>> In message from Andrey Slepuhin <andrey.slepuhin at t-platforms.ru> 
>>(Thu, 
>> 10 Aug 2006 21:17:37 +0400):
>> >So, the problem is with memory locking - see the failed mlock() in 
>>the 
>> >end of output. Regardless of rlimits you also may have memlock 
>> >capability enabled only for root - I don't remember exact /proc 
>>entry, 
>> >where you can disable it, but you can try to search it.
>> Yes, may be sysctl -w vm.disable_cap_mlock=1
>> (proposed here sometime ago) performs this job (I don't know exactly
>> the sense of this key), but my /proc don't have this file. I also 
>> didn't find any file (in /proc) having "mlock" context.
>---end quoted text---
>perhaps doing a "sysctl -a | less" and see what resembles
>vm.disable_cap_mlock (which is sles9 2.6 kernel) on the system you 
>are
>on? 
     Jimmy,
   I performed this thing few days ago: w/o any good ideas in my head.
  
>or if you are really daring and really trust your users (and the 
>software
>you are running in terms of security) perhaps you can try setting the
>suid bit on various pieces of software you are using. though its
>probably a bad idea :)

I'm probably crazy sysadmin (although usually my style is closer to 
paranoid) :-) - I had like thoughts also ;-) I think it'll be 
necessary (and enough) to add seteuid() (change to root) before 
VAPI_alloc_pd call in viainit.c, and to add "returning" seteuid() - 
after this call. 

But 1st of all (if it's kernel problem), may be there is some patch 
which enable mlock() for non-priveleggrd user - if it's right, that 
mlock() is "forbidden". Mellanox wrote that 2.4.21 kernel from Rocks 
distribution works w/whole IBGD-1.8.0 software collection.

Yours
Mikhail


>-- 
>Jimmy Tang
>Trinity Centre for High Performance Computing,
>Lloyd Building, Trinity College Dublin, Dublin 2, Ireland.
>http://www.tchpc.tcd.ie/