On 04/02/19 at 03:34pm, Oscar Salvador wrote:
> NODEMASK_ALLOC is used to allocate a nodemask bitmap, ant it does it by
~ and
> first determining whether it should be allocated in the stack or dinamically
dynamically^^
> depending on NODES_SHIFT.
> Right now, it goes the dynamic path whenever the nodemask_t is above 32
> bytes.
>
> Although we could bump it to a reasonable value, the largest a nodemask_t
> can get is 128 bytes, so since __nr_hugepages_store_common is called from
> a rather shore stack we can just get rid of the NODEMASK_ALLOC call here.
>
> This reduces some code churn and complexity.
>
> Signed-off-by: Oscar Salvador <[email protected]>
> ---
> mm/hugetlb.c | 36 +++++++++++-------------------------
> 1 file changed, 11 insertions(+), 25 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index f79ae4e42159..9cb2f91af897 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -2447,44 +2447,30 @@ static ssize_t __nr_hugepages_store_common(bool
> obey_mempolicy,
> unsigned long count, size_t len)
> {
> int err;
> - NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);
> + nodemask_t nodes_allowed, *n_mask;
>
> - if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) {
> - err = -EINVAL;
> - goto out;
> - }
> + if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
> + return -EINVAL;
>
> if (nid == NUMA_NO_NODE) {
> /*
> * global hstate attribute
> */
> if (!(obey_mempolicy &&
> - init_nodemask_of_mempolicy(nodes_allowed))) {
> - NODEMASK_FREE(nodes_allowed);
> - nodes_allowed = &node_states[N_MEMORY];
> - }
> - } else if (nodes_allowed) {
> + init_nodemask_of_mempolicy(&nodes_allowed)))
> + n_mask = &node_states[N_MEMORY];
> + else
> + n_mask = &nodes_allowed;
> + } else {
> /*
> * Node specific request. count adjustment happens in
> * set_max_huge_pages() after acquiring hugetlb_lock.
> */
> - init_nodemask_of_node(nodes_allowed, nid);
> - } else {
> - /*
> - * Node specific request, but we could not allocate the few
> - * words required for a node mask. We are unlikely to hit
> - * this condition. Since we can not pass down the appropriate
> - * node mask, just return ENOMEM.
> - */
> - err = -ENOMEM;
> - goto out;
> + init_nodemask_of_node(&nodes_allowed, nid);
> + n_mask = &nodes_allowed;
> }
>
> - err = set_max_huge_pages(h, count, nid, nodes_allowed);
> -
> -out:
> - if (nodes_allowed != &node_states[N_MEMORY])
> - NODEMASK_FREE(nodes_allowed);
> + err = set_max_huge_pages(h, count, nid, n_mask);
>
> return err ? err : len;
> }
> --
> 2.13.7
>
