On memory constrained systems, where a large amount of LUNs are assigned (say more enough to make multipath blossom to 70% of available memory space) forking would fail returning -ENOMEM. The kernel has enough free pages for the new process, but when it clones the new child process from the parent process space it accounts the parent process heap space against the child (which counts for more pages than there are free pages). Using vfork passes a flag to clone which will inhibit this calculation and instead check for free pages. The danger in using vfork is that the child could use the values from the parent, but fortunatly we don't do that and immediately call 'execve' swipping the process space free. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
