[PATCH 7/8] io_uring: add tw_ctx for io_uring_task

Hao Xu
2021-09-27T06:17:33Z

Add tw_ctx to represent whether there is only one ctx in
prior_task_list or not, this is useful in the next patch

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
---
fs/io_uring.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 48387ea47c15..596e9e885362 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -477,6 +477,7 @@ struct io_uring_task {
struct io_wq_work_list task_list;
struct callback_head task_work;
struct io_wq_work_list prior_task_list;
+ struct io_ring_ctx *tw_ctx;
unsigned int nr;
unsigned int prior_nr;
bool task_running;
@@ -2222,6 +2223,10 @@ static void io_req_task_work_add(struct io_kiocb *req, bool emergency)
if (emergency && tctx->prior_nr * MAX_EMERGENCY_TW_RATIO < tctx->nr) {
wq_list_add_tail(&req->io_task_work.node, &tctx->prior_task_list);
tctx->prior_nr++;
+ if (tctx->prior_nr == 1)
+ tctx->tw_ctx = req->ctx;
+ else if (tctx->tw_ctx && req->ctx != tctx->tw_ctx)
+ tctx->tw_ctx = NULL;
} else {
wq_list_add_tail(&req->io_task_work.node, &tctx->task_list);
}
@@ -2250,6 +2255,7 @@ static void io_req_task_work_add(struct io_kiocb *req, bool emergency)

spin_lock_irqsave(&tctx->task_lock, flags);
tctx->nr = tctx->prior_nr = 0;
+ tctx->tw_ctx = NULL;
tctx->task_running = false;
wq_list_merge(&tctx->prior_task_list, &tctx->task_list);
node = tctx->prior_task_list.first;
--
2.24.4