[PATCH 6/9] io-wq: fixed worker exit

Hao Xu
2022-04-29T10:19:28Z

Implement the fixed worker exit

Signed-off-by: Hao Xu <howeyxu@tencent.com>
---
fs/io-wq.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/fs/io-wq.c b/fs/io-wq.c
index a1a10fb204a7..2feff19970ca 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -259,6 +259,29 @@ static bool io_task_worker_match(struct callback_head *cb, void *data)
return worker == data;
}

+static void io_fixed_worker_exit(struct io_worker *worker)
+{
+ int *nr_fixed;
+ int index = worker->acct.index;
+ struct io_wqe *wqe = worker->wqe;
+ struct io_wqe_acct *acct = io_get_acct(wqe, index == 0, true);
+ struct io_worker **fixed_workers;
+
+ raw_spin_lock(&acct->lock);
+ fixed_workers = acct->fixed_workers;
+ if (!fixed_workers || worker->index == -1) {
+ raw_spin_unlock(&acct->lock);
+ return;
+ }
+ nr_fixed = &acct->nr_fixed;
+ /* reuse variable index to represent fixed worker index in its array */
+ index = worker->index;
+ fixed_workers[index] = fixed_workers[*nr_fixed - 1];
+ (*nr_fixed)--;
+ fixed_workers[index]->index = index;
+ raw_spin_unlock(&acct->lock);
+}
+
static void io_worker_exit(struct io_worker *worker)
{
struct io_wqe *wqe = worker->wqe;
@@ -682,6 +705,7 @@ static int io_wqe_worker(void *data)
struct io_wqe *wqe = worker->wqe;
struct io_wq *wq = wqe->wq;
bool last_timeout = false;
+ bool fixed = worker->flags & IO_WORKER_F_FIXED;
char buf[TASK_COMM_LEN];

worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
@@ -732,6 +756,8 @@ static int io_wqe_worker(void *data)

if (test_bit(IO_WQ_BIT_EXIT, &wq->state))
io_worker_handle_work(worker);
+ if (fixed)
+ io_fixed_worker_exit(worker);

audit_free(current);
io_worker_exit(worker);
--
2.36.0