Re: [PATCH] memory hotadd fixes [4/5] avoid check in acpi

From: Mika Penttilä
Date: Fri Aug 04 2006 - 04:24:49 EST

keith mannthey wrote:
On Fri, 2006-08-04 at 12:48 +0900, KAMEZAWA Hiroyuki wrote:
On Thu, 03 Aug 2006 20:23:46 -0700
keith mannthey <kmannth@xxxxxxxxxx> wrote:

What keeps 0xa0000000 to 0xa1000000 from being re-onlined by a bad call
to add_memory?
Usual sparsemem's add_memory() checks whether there are sections in
sparse_add_one_section(). then add_pages() returns -EEXIST (nothing to do).
And ioresouce collision check will finally find collision because 0-0xbffffff
resource will conflict with 0xa0000000 to 0xa10000000 area.
But, x86_64 's (not sparsemem) add_pages() doen't do collision check, so it panics.
I have paniced with your 5 patches while doing SPARSMEM.... I think
your 6th patch address the issues I was seeing.

with the 6 patches things work as expected. It is nice to have the
sysfs devices online the correct amount of memory.

I was broken without this patch because invalid add_memory calls are
made on by box (yet another issue) during boot.

I will build my patch set on top of your 6 patches.


Keith, are you working on the reserve hotadd case? It looks really broken, at the same time we both assume the hot add region contains RAM per e820 (use of reserve_bootmem_node()) and at the same time in other places (in reserve_hotadd()) that it may not contain RAM. And nodes_cover_memory() is broken no matter what we assume.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at