On Mon, 2016-06-20 at 21:14 -0500, Nathan Fontenot wrote: > On 06/20/2016 07:57 PM, Michael Ellerman wrote: > > On Mon, 2016-06-20 at 08:51 -0500, Nathan Fontenot wrote: > > > > > Auto online hotplugged memory > > > > > > A recent update (commit id 31bc3858ea3) to the core mm hotplug code > > > introduced the memhp_auto_online variable to allow for automatically > > > onlining memory that is added. > > > > > > This patch update the pseries memory hotplug code to enable this so that > > > any memory DLPAR added to the system is automatically onlined. The code > > > to add the memory block for memory added from add_memory() is removed as > > > this is not needed, the memory_add code does this. > > > > Is this a bug fix, or just a cleanup? > > Hmmm.. some cleanup and some new feature. The removal of the memblock_add() > call is a cleanup and the setting of the memhp_auto_online variable is > taking advantage of a feature I was not previously aware of.
OK. Looking at usage of memhp_auto_online it's not clear to me that you're supposed to be setting it in arch code. eg. if I build my kernel with CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE=n, I will expect it to not be onlined by default. Similarly if I boot with memhp_default_state=offline on the kernel command line. But this patch would then mean it is onlined by default. So that seems kind of confusing for users. I think instead we should be merging the bulk of this patch, but without the forced assignment to memhp_auto_online? cheers _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev