6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Felix Moessbauer <felix.moessbauer@xxxxxxxxxxx>
commit 84eacf177faa605853c58e5b1c0d9544b88c16fd upstream.
The io worker threads are userland threads that just never exit to the
userland. By that, they are also assigned to a cgroup (the group of the
creating task).
When creating a new io worker, this worker should inherit the cpuset
of the cgroup.
Fixes: da64d6db3bd3 ("io_uring: One wqe per wq")
Signed-off-by: Felix Moessbauer <felix.moessbauer@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240910171157.166423-3-felix.moessbauer@xxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/io-wq.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/io_uring/io-wq.c
+++ b/io_uring/io-wq.c
@@ -1157,6 +1157,7 @@ struct io_wq *io_wq_create(unsigned boun
{
int ret, node, i;
struct io_wq *wq;
+ cpumask_var_t allowed_mask;
if (WARN_ON_ONCE(!data->free_work || !data->do_work))
return ERR_PTR(-EINVAL);
@@ -1176,6 +1177,9 @@ struct io_wq *io_wq_create(unsigned boun
wq->do_work = data->do_work;
ret = -ENOMEM;
+ if (!alloc_cpumask_var(&allowed_mask, GFP_KERNEL))
+ goto err;
+ cpuset_cpus_allowed(current, allowed_mask);
for_each_node(node) {
struct io_wqe *wqe;
int alloc_node = node;
@@ -1188,7 +1192,8 @@ struct io_wq *io_wq_create(unsigned boun
wq->wqes[node] = wqe;
if (!alloc_cpumask_var(&wqe->cpu_mask, GFP_KERNEL))
goto err;
- cpumask_copy(wqe->cpu_mask, cpumask_of_node(node));
+ if (!cpumask_and(wqe->cpu_mask, cpumask_of_node(node), allowed_mask))
+ cpumask_copy(wqe->cpu_mask, allowed_mask);
wqe->node = alloc_node;
wqe->acct[IO_WQ_ACCT_BOUND].max_workers = bounded;
wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers =
@@ -1222,6 +1227,7 @@ err:
free_cpumask_var(wq->wqes[node]->cpu_mask);
kfree(wq->wqes[node]);
}
+ free_cpumask_var(allowed_mask);
err_wq:
kfree(wq);
return ERR_PTR(ret);
