Cluster Mask

(by Moshe Bar)

Several people have asked for a feature in openMosix which allows to specifiy to which nodes a given process and it's children can migrate and to which nodes it cannot.

Simone Ettore has just committed a new patch to the CVS which allows you to do just that.

Here is how it works:

• /proc/[pid]/migfilter enable/disable the capability of filter migration.

• /proc/[pid]/mignodes is a bit-list of nodes. The bit position of a node is calculated as 2^(PE-1). PE is node number.

• /proc/[pid]/migpolicy is the policy of the filtering: 0=DENY: the process can migrate in all nodes except when the relative bit on mignodes is 1 1=ALLOW: the process can migrate in all nodes where the relative bit on mignodes is 1

We are shortly going to release also a simple user-land tool to set the node mask, but I would like you guys to give it a try asap before we release it as openMosix 2.4.20-3.