On Tue, Feb 11, 2014 at 09:25:14AM +0000, Mel Gorman wrote: > On Mon, Feb 10, 2014 at 06:54:20PM -0800, David Rientjes wrote: > > On Mon, 10 Feb 2014, Luiz Capitulino wrote: > > > > > HugeTLB command-line option hugepages= allows the user to specify how many > > > huge pages should be allocated at boot. On NUMA systems, this argument > > > automatically distributes huge pages allocation among nodes, which can > > > be undesirable. > > > > > > > And when hugepages can no longer be allocated on a node because it is too > > small, the remaining hugepages are distributed over nodes with memory > > available, correct? > > > > > The hugepagesnid= option introduced by this commit allows the user > > > to specify which NUMA nodes should be used to allocate boot-time HugeTLB > > > pages. For example, hugepagesnid=0,2,2G will allocate two 2G huge pages > > > from node 0 only. More details on patch 3/4 and patch 4/4. > > > > > > > Strange, it would seem better to just reserve as many hugepages as you > > want so that you get the desired number on each node and then free the > > ones you don't need at runtime. You have to know the behaviour of the allocator, and rely on that to allocate the exact number of 1G hugepages on a particular node. Is that desired in constrast with specifying the exact number, and location, of hugepages to allocated? > Or take a stab at allocating 1G pages at runtime. It would require > finding properly aligned 1Gs worth of contiguous MAX_ORDER_NR_PAGES at > runtime. I would expect it would only work very early in the lifetime of > the system but if the user is willing to use kernel parameters to > allocate them then it should not be an issue. Can be an improvement on top of the current patchset? Certain use-cases require allocation guarantees (even if that requires kernel parameters). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>