Messages in this thread | | | Date | Wed, 30 May 2012 20:46:38 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH 0/6] mempolicy memory corruption fixlet |
| |
On Wed, May 30, 2012 at 01:34:21PM -0500, Christoph Lameter wrote: > On Wed, 30 May 2012, Linus Torvalds wrote: > > > On Wed, May 30, 2012 at 2:02 AM, <kosaki.motohiro@gmail.com> wrote: > > > > > > So, I think we should reconsider about shared mempolicy completely. > > > > Quite frankly, I'd prefer that approach. The code is subtle and > > horribly bug-fraught, and I absolutely detest the way it looks too. > > Reading your patches was actually somewhat painful. > > It is so bad mostly because the integration of shared memory policies with > cpusets is not really working. Using either in isolation is ok especially > shared mempolicies do not play well with cpusets.
Yes the cpusets did some horrible things.
I always regretted that cpusets were no done with custom node lists. That would have been much cleaner and also likely faster than what we have.
> > If we could just remove the support for it entirely, that would be > > *much* preferable to continue working with this code. > > Well shm support needs memory policies to spread data across nodes etc. > AFAICT support was put in due to requirements to support large database > vendors (oracle). Andi?
Yes we need shared policy for the big databases.
Maybe we could stop supporting cpusets with that though. Not sure they really use that.
> Its not going to be easy to remove.
Shared policies? I don't think you can remove them. cpusets+shared policy? maybe, but still will be hard.
-Andi
>
-- ak@linux.intel.com -- Speaking for myself only.
| |