Re: [PATCH] memory hotadd fixes [4/5] avoid check in acpi
From: KAMEZAWA Hiroyuki
Date: Thu Aug 03 2006 - 23:44:38 EST
On Thu, 03 Aug 2006 20:23:46 -0700
keith mannthey <kmannth@xxxxxxxxxx> wrote:
> On Fri, 2006-08-04 at 12:13 +0900, KAMEZAWA Hiroyuki wrote:
> > On Thu, 03 Aug 2006 20:00:08 -0700
> > keith mannthey <kmannth@xxxxxxxxxx> wrote:
> > > > > What protecting is there for calling add_memory on an already present
> > > > > memory range?
> > > > >
> > > > For example, considering ia64, which has 1Gbytes section...
> > >
> > > Maybe 1gb sections is too large?
> > >
> > ia64 machines sometimes to have crazy big memory...so 1gb section is requested.
> > Configurable section_size for small machines was rejected in old days.
> My HW supports about 512gb......
> What if you add a partial section. Then online in sysfs and add another
> section? messy....
Once a section is onlined, it cannot be re-onlined. My patch just helps memory holes
in "a" memory hot add event.
Our firmware team tells us they may create small memory holes in contiguous memory...
> > > 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.
Thank you for testing.
BTW, could you send your current config ? looks I should visit source code again..
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