On 6/9/23 13:20, Hao Xu wrote:
From: Hao Xu <howeyxu@xxxxxxxxxxx>
Add a new type io-wq worker IO_WORKER_F_FIXED, this type of worker
exists during the whole io-wq lifecycle.
Signed-off-by: Hao Xu <howeyxu@xxxxxxxxxxx>
---
io_uring/io-wq.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c
index 1717f1465613..7326fef58ca7 100644
--- a/io_uring/io-wq.c
+++ b/io_uring/io-wq.c
@@ -30,6 +30,7 @@ enum {
IO_WORKER_F_FREE = 4, /* worker on free list */
IO_WORKER_F_BOUND = 8, /* is doing bounded work */
IO_WORKER_F_EXIT = 16, /* worker is exiting */
+ IO_WORKER_F_FIXED = 32, /* is a fixed worker */
};
enum {
@@ -598,6 +599,11 @@ static bool is_worker_exiting(struct io_worker *worker)
return worker->flags & IO_WORKER_F_EXIT;
}
+static bool is_fixed_worker(struct io_worker *worker)
+{
+ return worker->flags & IO_WORKER_F_FIXED;
+}
You move it up in Patch 5/11, I suggest to move it to the top of the
file here.
static int io_wq_worker(void *data)
{
struct io_worker *worker = data;
@@ -622,8 +628,13 @@ static int io_wq_worker(void *data)
/*
* Last sleep timed out. Exit if we're not the last worker,
* or if someone modified our affinity.
+ * Note: fixed worker always have same lifecycle as io-wq
+ * itself, and cpu affinity setting doesn't work well for
+ * fixed worker, they can be manually reset to cpu other than
+ * the cpuset indicated by io_wq_worker_affinity()
*/
- if (last_timeout && (exit_mask || acct->nr_workers > 1)) {
+ if (!is_fixed_worker(worker) && last_timeout &&
+ (exit_mask || acct->nr_workers > 1)) {
acct->nr_workers--;
raw_spin_unlock(&wq->lock);
__set_current_state(TASK_RUNNING);
If there is no work it'll continue to loop every
WORKER_IDLE_TIMEOUT (5 * HZ), which sounds troublesome with many
workers in the system.
tm = is_fixed_worker(worker) ? MAX_SCHEDULE_TIMEOUT : WORKER_IDLE_TIMEOUT;
schedule_timeout(tm);
Maybe?
--
Pavel Begunkov
