On Fri, Aug 11, 2017 at 02:07:51PM +0530, Aneesh Kumar K.V wrote:
Reza Arbab <ar...@linux.vnet.ibm.com> writes:
On Thu, Aug 10, 2017 at 02:53:48PM +0530, Bharata B Rao wrote:
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index f830562..24ecf53 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -524,6 +524,7 @@ static int __init early_init_dt_scan_drconf_memory(unsigned
long node)
size = 0x80000000ul - base;
}
memblock_add(base, size);
+ memblock_mark_hotplug(base, size);
} while (--rngs);
}
memblock_dump_all();
Doing this has the effect of putting all the affected memory into
ZONE_MOVABLE. See find_zone_movable_pfns_for_nodes(). This means no
kernel allocations can occur there. Is that okay?
So the thinking here is any memory identified via ibm,dynamic-memory can
be hot removed later. Hence the need to add them lmb size, because our
hotplug framework remove them in lmb size. If we want to support
hotunplug, then we will have to make sure kernel allocation doesn't
happen in that region right ?
Yes, the net result is that this memory can now be hotremoved. I just
wanted to point out that the patch doesn't only change the granularity
of addition--it also causes the memory to end up in a different zone
(when using movable_node).
With the above i would consider not marking it hotplug was a bug before
?
Sure, that's reasonable.
--
Reza Arbab
