On 07/13/2010 10:26 PM, Dave Hansen wrote: > On Wed, 2010-07-14 at 09:35 +0900, KAMEZAWA Hiroyuki wrote: >> 2. I'd like to write a configfs module for handling memory hotplug even >> when >> sysfs directroy is not created. >> Because configfs support rmdir/mkdir, the user (ppc's daemon?) has to do >> >> When offlining section X. >> # insmod configfs_memory.ko >> # mount -t configfs none /configfs >> # mkdir /configfs/memoryX >> # echo offline > /configfs/memoryX/state >> # rmdir /configfs/memoryX >> >> And making this operation as the default bahavior for all arch's memory >> hotplug may >> be better... >> >> Dave, how do you think ? Because ppc guys uses "probe" interface already, >> this can be handled... no ? > > I think creating a interface to duplicate the existing sysfs one is a > bad idea. I also think removing the existing sysfs one isn't feasible > since there are users, and it's truly part of the ABI. So, I'm not > really a fan on the configfs interface. :( > > I really do think the sysfs interface is fixable. We should at least > give it a good shot before largely duplicating its functionality.
I agree with Dave, I don't think another memory hotplug interface is needed. I am working to update the patchset to remove the split functionality and fix other items commented on. this new patch will just split the memory_block structure so that a memory_block can span multiple memory sections. Kame, I understand that offlining 16 MB is easier than 256 MB. From the ppc perspective though, we are still offlining 256 MB. We do memory add/remove on LMB size chunks, so we have to add/remove all of the memory sections contained in an LMB. If any one memory section covered by a LMB fails to add/remove, we restore the memory sections to their orignal state an fail the add/remove operation. NOTE: the code doing this is not in the kernel, but in the user-space drmgr command (from powerpc-utils package). -Nathan _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
