On Mon, Dec 14, 2015 at 6:52 AM, Jeff Moyer <jmoyer@xxxxxxxxxx> wrote: > Dan Williams <dan.j.williams@xxxxxxxxx> writes: > >> In the meantime, I expect some would say DAX is a toy as long as it >> continues to fail at DMA. > > I suppose this is the crux of it. Given that we may be able to migrate > away from the allocation of storage for temporary data structures in the > future, and given that admin tooling could hide the undesirable > configurations, this approach seems workable. Here's my current thoughts on the tooling for namespace creation: ndctl create-namespace That command by default will create a maximally sized pmem namespace and set up the struct page memmap by default i.e. it defaults to the following parameters: ndctl create-namespace --type=pmem --mode=memory The other options for 'mode' are 'safe' and 'raw' where 'safe' establishes a btt, and 'raw' exposes the full un-decorated capacity of the namespace. If you have a pre-existing 'raw' mode pmem namespace, you can convert it to be enabled for dma, and other capabilities typical memory possesses, with the following: ndctl create-namespace --mode=memory -r namespace0.0 -- 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>