On Mon, Dec 27, 2010 at 02:53:47AM -0800, David Rientjes wrote: > On Mon, 27 Dec 2010, Ben Blum wrote: > > > > I'm not sure what the benefit of defining it as a macro would be. You're > > > defining these statically allocated nodemasks so they have file scope, I > > > hope (so they can be shared amongst the users who synchronize on > > > cgroup_lock() already). > > > > In the attach() case, yes, but in other cases I was thinking they could > > be put on the stack if CONFIG_NODES_SHIFT < 8, and static but still > > per-function otherwise. Or should all the functions share the same > > global nodemask? > > > > I think it would be appropriate to use a shared nodemask with file scope > whenever you have cgroup_lock() to avoid the unnecessary kmalloc() even > with GFP_KERNEL. Cpusets are traditionally used on very large machines in > the first place, so there is a higher likelihood that > CONFIG_NODES_SHIFT > 8 whenever CONFIG_CPUSETS is enabled. > > All users of NODEMASK_ALLOC() should be protected by cgroup_lock() other > than cpuset_sprintf_memlist(), right? That should be the only remaining > user of NODEMASK_ALLOC() and works well since it can return -ENOMEM. Just checked; that looks right. Perhaps I should add cgroup_is_locked() in cgroup.c and BUG_ON() checks for it in those functions, too? -- Ben _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
