Re: [PATCH 1/2] mm: fix bugs of mpol_rebind_nodemask()

From: David Rientjes
Date: Fri Apr 23 2010 - 04:45:45 EST


On Fri, 23 Apr 2010, Miao Xie wrote:

> Suppose the current mempolicy nodes is 0-2, we can remap it from 0-2 to 2,
> then we can remap it from 2 to 1, but we can't remap it from 2 to 0-2.
>
> that is to say it can't be remaped to a large set of allowed nodes, and the task
> just can use the small set of nodes for ever, even the large set of nodes is allowed,
> I think it is unreasonable.
>

That's been the behavior for at least three years so changing it from
under the applications isn't acceptable, see
Documentation/vm/numa_memory_policy.txt regarding mempolicy rebinds and
the two flags that are defined that can be used to adjust the behavior.

The pol->v.nodes = nodes_empty(tmp) ? *nodes : tmp fix is welcome,
however, as a standalone patch.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/