On Thu, 20 May 2021, Feng Tang wrote:
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index d79fa29..1964cca 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -2098,7 +2098,7 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask)
> *
> * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
> * policy. Otherwise, check for intersection between mask and the policy
> - * nodemask for 'bind' or 'interleave' policy. For 'preferred' or 'local'
> + * nodemask for 'bind' policy. For 'interleave', 'preferred' or 'local'
> * policy, always return true since it may allocate elsewhere on fallback.
> *
> * Takes task_lock(tsk) to prevent freeing of its mempolicy.
> @@ -2111,29 +2111,13 @@ bool mempolicy_nodemask_intersects(struct task_struct *tsk,
>
> if (!mask)
> return ret;
> +
> task_lock(tsk);
> mempolicy = tsk->mempolicy;
> - if (!mempolicy)
> - goto out;
> -
> - switch (mempolicy->mode) {
> - case MPOL_PREFERRED:
> - /*
> - * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
> - * allocate from, they may fallback to other nodes when oom.
> - * Thus, it's possible for tsk to have allocated memory from
> - * nodes in mask.
> - */
> - break;
> - case MPOL_BIND:
> - case MPOL_INTERLEAVE:
> + if (mempolicy && mempolicy->mode == MPOL_BIND)
> ret = nodes_intersects(mempolicy->v.nodes, *mask);
If MPOL_INTERLEAVE is deemed only a suggestion, the same could be
considered true of MPOL_BIND intersection as well, no?
> - break;
> - default:
> - BUG();
> - }
> -out:
> task_unlock(tsk);
> +
> return ret;
> }
>
> --
> 2.7.4
>
>
