Mac Pro 12 Core (24 treads) and only 8 working, others saying Wait for shared Memory

Questions and Answers : Macintosh : Mac Pro 12 Core (24 treads) and only 8 working, others saying Wait for shared Memory
Message board moderation

To post messages, you must log in.

AuthorMessage
Profile Luigi LAPLACE

Send message
Joined: 10 Feb 12
Posts: 2
Credit: 448,104
RAC: 81
France
Message 1829210 - Posted: 8 Nov 2016, 15:38:18 UTC

Hello everybody !

I have a problem with Boinc everytime I launch it, only 8 tasks are running together + the openCL one.

But, I'm using a 12 core Mac Pro (24 tread usable) with 24 GB of RAM and a GTX680.
I don't undrestand because it doesn't use all my RAM.

Does anyone have an idea ?
ID: 1829210 · Report as offensive
Profile Ageless
Avatar

Send message
Joined: 9 Jun 99
Posts: 14181
Credit: 3,471,033
RAC: 1,728
Netherlands
Message 1829214 - Posted: 8 Nov 2016, 16:00:41 UTC - in response to Message 1829210.  

Having loads of memory doesn't mean you have enough shared memory.

From this BOINC FAQ:
BOINC science applications use shared memory to communicate with the core client, and a certain amount is reserved for each current task, whether running or waiting. The default configuration of a multi-CPU Mac (regardless of how much RAM is installed) is sometimes inadequate to support several projects at once.

If you get this error message, which is usually followed by a “Couldn't start or resume: -144” error in the current computation, it may help to set your BOINC general preference “Leave applications in memory while suspended?” to no; however, the problem will probably just become less frequent rather than being solved, and moreover some projects’ applications, those that save checkpoints infrequently (or erratically), may not take well to this setting.

A better solution is available—if you don’t mind reconfiguring your system’s kernel a little. The method, accompanied by a more detailed description of the issue, is outlined in Configuring Shared Memory on Mac OS X from Spy Hill Research (hosts of the BOINC Pirates@home project). It involves creating a text file “/etc/sysctl.conf” that contains the following commands:

kern.sysv.shmmax=16777216
kern.sysv.shmmin=1
kern.sysv.shmmni=128
kern.sysv.shmseg=32
kern.sysv.shmall=4096

and rebooting the computer. This will quadruple the default allocation of shared memory.

Note that the problem may manifest with slightly different error messages: “Can't create shared memory: system shmat” followed by “Couldn't start or resume: -146”.

Jord

Ancient Astronaut Theorists suggest that in many ways, you can be considered an alien conspiracy!
ID: 1829214 · Report as offensive
Profile Luigi LAPLACE

Send message
Joined: 10 Feb 12
Posts: 2
Credit: 448,104
RAC: 81
France
Message 1829284 - Posted: 9 Nov 2016, 9:33:06 UTC - in response to Message 1829214.  

Thank you, I found it last night, but, thank you so much !
ID: 1829284 · Report as offensive

Questions and Answers : Macintosh : Mac Pro 12 Core (24 treads) and only 8 working, others saying Wait for shared Memory


 
©2017 University of California
 
SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.