lkml.org 
[lkml]   [2021]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v6 1/6] mm/mempolicy: Add MPOL_PREFERRED_MANY for multiple preferred nodes
On Thu, Jul 29, 2021 at 06:21:19PM +0200, Michal Hocko wrote:
> On Thu 29-07-21 23:12:42, Feng Tang wrote:
> > On Thu, Jul 29, 2021 at 03:38:44PM +0200, Michal Hocko wrote:
> [...]
> > > Also the
> > > semantic to give nodes some ordering based on their numbers sounds
> > > rather weird to me.
> >
> > I agree, and as I admitted in the first reply, this need to be fixed.
>
> OK. I was not really clear that we are on the same page here.
>
> > > The semantic I am proposing is to allocate from prefered nodes in
> > > distance order starting from the local node.
> >
> > So the plan is:
> > * if the local node is set in 'prefer-many's nodemask, then chose
> > * otherwise chose the node with the shortest distance to local node
> > ?
>
> Yes and what I am trying to say is that you will achieve that simply by
> doing the following in policy_node:
> if (policy->mode == MPOL_PREFERRED_MANY)
> return nd;

One thing is, it's possible that 'nd' is not set in the preferred
nodemask.

For policy_node(), most of its caller use the local node id as 'nd'
parameter. For HBM and PMEM memory nodes, they are cpuless nodes,
so they will not be a 'local node', but some use cases only prefer
these nodes.

Thanks,
Feng

> --
> Michal Hocko
> SUSE Labs

\
 
 \ /
  Last update: 2021-07-30 05:06    [W:0.100 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site