On Thu, Feb 01, 2024 at 09:55:07AM +0800, Huang, Ying wrote:

quoted

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index b1437396c357..dfd097009606 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c

@@ -2391,7 +2391,7 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp,
        unsigned long nr_allocated = 0;
        unsigned long rounds;
        unsigned long node_pages, delta;
-       u8 __rcu *table, *weights, weight;
+       u8 __rcu *table, __rcu *weights, weight;

The __rcu usage can be checked with `sparse` directly.  For example,

make C=1 mm/mempolicy.o

More details can be found in

https://www.kernel.org/doc/html/latest/dev-tools/sparse.html

Per my understanding, we shouldn't use "__rcu" here.  Please search
"__rcu" in the following document.

https://www.kernel.org/doc/html/latest/RCU/checklist.html

Thanks for this, I will sort this out and respond here with changes
before v5.

quoted

@@ -2460,17 +2454,10 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp,
                        node_pages += weight;
                        delta -= weight;
                } else if (delta) {
+                       /* when delta is deleted, resume from that node */

                                           ~~~~~~~
                                           depleted?

ack.

quoted

+retry:
+       /* to prevent miscount use tsk->mems_allowed_seq to detect rebind */
+       cpuset_mems_cookie = read_mems_allowed_begin();
        if (!current->il_weight || !node_isset(node, policy->nodes)) {
                node = next_node_in(node, policy->nodes);

node will be changed in the loop.  So we need to change the logic here.

Good catch, stupid mistake. ack.

quoted

@@ -2388,10 +2401,17 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp,
        int prev_node;
        int i;

+

Change by accident?

ack.

~Gregory