unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
1
Fork 0
Code Pull requests 5 Wiki Activity

io_uring/sqpoll: use the correct check for pending task_work

Browse source 
A previous commit moved to using just the private task_work list for
SQPOLL, but it neglected to update the check for whether we have
pending task_work. Normally this is fine as we'll attempt to run it
unconditionally, but if we race with going to sleep AND task_work
being added, then we certainly need the right check here.

Fixes: af5d68f889 ("io_uring/sqpoll: manage task_work privately")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2024-02-14 13:57:20 -07:00
parent 78f9b61bd8
commit c8d8fc3b2d
1 changed files with 8 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
io_uring/sqpoll.c
View file

@ -246,6 +246,13 @@ static unsigned int io_sq_tw(struct llist_node **retry_list, int max_entries)
return count;
}
static bool io_sq_tw_pending(struct llist_node *retry_list)
{
struct io_uring_task *tctx = current->io_uring;
return retry_list || !llist_empty(&tctx->task_list);
}
static int io_sq_thread(void *data)
{
struct llist_node *retry_list = NULL;
@ -301,7 +308,7 @@ static int io_sq_thread(void *data)
}
prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE);
if (!io_sqd_events_pending(sqd) && !task_work_pending(current)) {
if (!io_sqd_events_pending(sqd) && !io_sq_tw_pending(retry_list)) {
bool needs_sched = true;
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {