On Tuesday 14 January 2014 08:17 AM, Grygorii Strashko wrote: > Hi Philipp, > > On 01/13/2014 03:03 PM, Philipp Hachtmann wrote: >> Add a new memory state "nomap" to memblock. This can be used to truncate >> the usable memory in the system without forgetting about what is really >> installed. > > > Sorry, but this solution looks a bit complex (and probably wrong - from design point of view)) > if you need just to fix memblock_start_of_DRAM()/memblock_end_of_DRAM() APIs. > > More over, other arches use at least below APIs: > - memblock_is_region_memory() !!! > - for_each_memblock(memory, reg) !!! > - __next_mem_pfn_range() !!! > - memblock_phys_mem_size() > - memblock_mem_size() > - memblock_start_of_DRAM() > - memblock_end_of_DRAM() > with assumption that "memory" regions array have been updated > when mem block is stolen (no-mapped), as result this change may > have unpredictable side effects :( if these new APIs > will be re-used (for ARM arch, as example). > > You can take a look on how ARM is using arm_memblock_steal() - > the stolen memory is not accounted any more. > I was also wondering instead of nomap state, the memblock_add/remove() will do the same trick. arm_memblock_steal() wrapper does achieve similar functionality of reserving the DRAM without mapping it into the Linux. Why not just use the same idea ? Regards, Santosh -- 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>