On 2014/6/12 6:08, David Rientjes wrote: > On Wed, 11 Jun 2014, Zhang Zhen wrote: > >> Hi, >> >> Now we can hot-add memory by >> >> % echo start_address_of_new_memory > /sys/devices/system/memory/probe >> >> Then, [start_address_of_new_memory, start_address_of_new_memory + >> memory_block_size] memory range is hot-added. >> >> But we can only hot-add *one section one time* by this way. >> Whether we can add an argument on behalf of the count of the sections to add >> ? >> So we can can hot-add *several sections one time*. Just like: >> > > Not necessarily true, it depends on sections_per_block. Don't believe > Documentation/memory-hotplug.txt that suggests this is only for powerpc, > x86 and sh allow this interface as well. > >> % echo start_address_of_new_memory count_of_sections > >> /sys/devices/system/memory/probe >> >> Then, [start_address_of_new_memory, start_address_of_new_memory + >> count_of_sections * memory_block_size] memory range is hot-added. >> >> If this proposal is reasonable, i will send a patch to realize it. >> > > The problem is knowing how much memory is being onlined so that you can > definitively determine what count_of_sections should be. The number of > pages per memory section depends on PAGE_SIZE and SECTION_SIZE_BITS which > differ depending on the architectures that support this interface. So if > you support count_of_sections, it would return errno even though you have > onlined some sections. > Hum, sorry. My expression is not right. The count of sections one time hot-added depends on sections_per_block.
Now we are porting the memory-hotplug to arm. But we can only hot-add *fixed number of sections one time* on particular architecture. Whether we can add an argument on behalf of the count of the blocks to add ? % echo start_address_of_new_memory count_of_blocks > /sys/devices/system/memory/probe Then, [start_address_of_new_memory, start_address_of_new_memory + count_of_blocks * memory_block_size] memory range is hot-added. So user don't need execute several times of echo when they want to hot add multi-block size memory. Any comments are welcome. Best regards! > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
