On 10/24/2016 06:22 PM, Anshuman Khandual wrote: > On 10/24/2016 10:39 PM, Dave Hansen wrote: >>> +#ifdef CONFIG_COHERENT_DEVICE >>>> +#define node_cdm(nid) (NODE_DATA(nid)->coherent_device) >>>> +#define set_cdm_isolation(nid) (node_cdm(nid) = 1) >>>> +#define clr_cdm_isolation(nid) (node_cdm(nid) = 0) >>>> +#define isolated_cdm_node(nid) (node_cdm(nid) == 1) >>>> +#else >>>> +#define set_cdm_isolation(nid) () >>>> +#define clr_cdm_isolation(nid) () >>>> +#define isolated_cdm_node(nid) (0) >>>> +#endif >> FWIW, I think adding all this "cdm" gunk in the names is probably a bad >> thing. >> >> I can think of other memory types that are coherent, but >> non-device-based that might want behavior like this. > > Hmm, I was not aware about non-device-based coherent memory. Could you > please name some of them ? If thats the case we need to change CDM to > some thing which can accommodate both device and non device based > coherent memory. May be like "Differentiated/special coherent memory". > But it needs to communicate that its not system RAM. Thats the idea. Intel has some stuff called MCDRAM. It's described in detail here: > https://software.intel.com/en-us/articles/mcdram-high-bandwidth-memory-on-knights-landing-analysis-methods-tools You can also Google around for more information. I believe Samsung has a technology called High Bandwidth Memory (HBM) that's already a couple of generations old that sounds similar. -- 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>