[PATCH v3 2/2] io_uring/io-wq: inherit cpuset of cgroup in io worker

From: Felix Moessbauer
Date: Tue Sep 10 2024 - 13:12:36 EST


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>
---
io_uring/io-wq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c
index c7055a8895d7..a38f36b68060 100644
--- a/io_uring/io-wq.c
+++ b/io_uring/io-wq.c
@@ -1168,7 +1168,7 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)

if (!alloc_cpumask_var(&wq->cpu_mask, GFP_KERNEL))
goto err;
- cpumask_copy(wq->cpu_mask, cpu_possible_mask);
+ cpuset_cpus_allowed(data->task, wq->cpu_mask);
wq->acct[IO_WQ_ACCT_BOUND].max_workers = bounded;
wq->acct[IO_WQ_ACCT_UNBOUND].max_workers =
task_rlimit(current, RLIMIT_NPROC);
--
2.39.2