On Tue, Oct 06, 2009 at 12:28:49PM -0400, Lee Schermerhorn wrote:
> On Tue, 2009-10-06 at 18:01 +0200, Andi Kleen wrote:
> > On Mon, Oct 05, 2009 at 11:19:24PM -0400, Lee Schermerhorn wrote:
> > > [PATCH 11/11] hugetlb: offload [un]registration of sysfs attr to worker thread
> > >
> > > Against: 2.6.31-mmotm-090925-1435
> > >
> > > New in V6
> > >
> > > V7: + remove redundant check for memory{ful|less} node from
> > > node_hugetlb_work(). Rely on [added] return from
> > > hugetlb_register_node() to differentiate between transitions
> > > to/from memoryless state.
> > >
> > > This patch offloads the registration and unregistration of per node
> > > hstate sysfs attributes to a worker thread rather than attempt the
> > > allocation/attachment or detachment/freeing of the attributes in
> > > the context of the memory hotplug handler.
> >
> > Why this change? The hotplug handler should be allowed to sleep, shouldn't it?
>
> Andy: perhaps it can. I'm not familiar with hotplug, so I followed a
> pattern found elsewhere. I created a separate patch in case someone
> familiar with this area says I don't need it.
At least ACPI already puts it on a work queue.
> >
> > > N.B., Only tested build, boot, libhugetlbfs regression.
> > > i.e., no memory hotplug testing.
> >
> > Yes, you have to because I know for a fact it's broken (outside your code) :)
>
> We need to be able to remove all memory from a node without that node
> disappearing [as I think it does on x86_64] to even exercise this code.
Are you sure? x86-64 doesn't support full node hotplug afaik.
> I think some ia64 platforms can do that, perhaps others.
I've been thinking about adding a hotadd regression test at boot time that
only adds memory to nodes later after boot. That would at least test hotadd
(and hot-removal is dubious anyways).
That wouldn't be real node hotadd, but at least memory hotadd of all
to a node (which doesn't work currently)
-Andi
P.S.: You can add Reviewed-by for me to the other patches if you want.
--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
--
To unsubscribe from this list: send the line "unsubscribe linux-numa" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
