On 2014/8/23 6:16, Andrew Morton wrote: > On Mon, 18 Aug 2014 11:25:36 +0800 Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx> wrote: > >> On 2014/8/16 5:37, Toshi Kani wrote: >>> On Wed, 2014-08-13 at 12:10 +0800, Zhang Zhen wrote: >>>> Currently memory-hotplug has two limits: >>>> 1. If the memory block is in ZONE_NORMAL, you can change it to >>>> ZONE_MOVABLE, but this memory block must be adjacent to ZONE_MOVABLE. >>>> 2. If the memory block is in ZONE_MOVABLE, you can change it to >>>> ZONE_NORMAL, but this memory block must be adjacent to ZONE_NORMAL. >>>> >>>> With this patch, we can easy to know a memory block can be onlined to >>>> which zone, and don't need to know the above two limits. >>>> >>>> Updated the related Documentation. >>>> >>>> Change v1 -> v2: >>>> - optimize the implementation following Dave Hansen's suggestion >>>> >>>> Signed-off-by: Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx> >>>> --- >>>> Documentation/ABI/testing/sysfs-devices-memory | 8 ++++ >>>> Documentation/memory-hotplug.txt | 4 +- >>>> drivers/base/memory.c | 62 ++++++++++++++++++++++++++ >>>> include/linux/memory_hotplug.h | 1 + >>>> mm/memory_hotplug.c | 2 +- >>>> 5 files changed, 75 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory >>>> index 7405de2..2b2a1d7 100644 >>>> --- a/Documentation/ABI/testing/sysfs-devices-memory >>>> +++ b/Documentation/ABI/testing/sysfs-devices-memory >>>> @@ -61,6 +61,14 @@ Users: hotplug memory remove tools >>>> http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils >>>> >>>> >>>> +What: /sys/devices/system/memory/memoryX/zones_online_to >>> >>> I think this name is a bit confusing. How about "valid_online_types"? >>> >> Thanks for your suggestion. >> >> This patch has been added to -mm tree. >> If most people think so, i would like to modify the interface name. >> If not, let's leave it as it is. > > Yes, the name could be better. Do we actually need "online" in there? > How about "valid_zones"? Ok, i will change it to valid_zones. > > Also, it's not really clear to me why we need this sysfs file at all. > Do people really read sysfs files, make onlining decisions and manually > type in commands? Or is this stuff all automated? If the latter then > the script can take care of all this? For example, attempt to online > the memory into the desired zone and report failure if that didn't > succeed? Just like Dave Hansen says, the scripts should be changed when we add a new zone type. And ZONE_MOVABLE may be missed by the scripts writer. > > IOW, please update the changelog to show > > a) example output from > /sys/devices/system/memory/memoryX/whatever-we-call-it and > > b) example use-cases which help reviewers understand why this > feature will be valuable to users. Sorry, this patch has been added to -next tree. I can't modify the changelog. > > Also, please do address the error which Yasuaki Ishimatsu identified. > Yeah, i have been waiting for http://ozlabs.org/~akpm/mmots/broken-out/memory-hotplug-add-sysfs-zones_online_to-attribute-fix-2.patch added to -mm tree. So i can send a patch based on -mm tree to address the error which Yasuaki Ishimatsu identified. Otherwise, conflicts may occur. Thanks! > > . > -- 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>