diff options
| author | Stefano Garzarella <sgarzare@redhat.com> | 2020-02-21 16:42:16 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-28 17:22:27 +0100 |
| commit | 8eb92c122840227cce98d301f77f2ba4d3810264 (patch) | |
| tree | 20013652714028c35bfb5764568559802df497d2 /fs/io_uring.c | |
| parent | b0f5f25c5541a812e63fe147fefa2cb0e9bd0530 (diff) | |
io_uring: prevent sq_thread from spinning when it should stop
commit 7143b5ac5750f404ff3a594b34fdf3fc2f99f828 upstream.
This patch drops 'cur_mm' before calling cond_resched(), to prevent
the sq_thread from spinning even when the user process is finished.
Before this patch, if the user process ended without closing the
io_uring fd, the sq_thread continues to spin until the
'sq_thread_idle' timeout ends.
In the worst case where the 'sq_thread_idle' parameter is bigger than
INT_MAX, the sq_thread will spin forever.
Fixes: 6c271ce2f1d5 ("io_uring: add submission polling")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 4797acd11b86..ed9a551882cf 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2732,16 +2732,6 @@ static int io_sq_thread(void *data) to_submit = io_sqring_entries(ctx); if (!to_submit) { /* - * We're polling. If we're within the defined idle - * period, then let us spin without work before going - * to sleep. - */ - if (inflight || !time_after(jiffies, timeout)) { - cond_resched(); - continue; - } - - /* * Drop cur_mm before scheduling, we can't hold it for * long periods (or over schedule()). Do this before * adding ourselves to the waitqueue, as the unuse/drop @@ -2753,6 +2743,16 @@ static int io_sq_thread(void *data) cur_mm = NULL; } + /* + * We're polling. If we're within the defined idle + * period, then let us spin without work before going + * to sleep. + */ + if (inflight || !time_after(jiffies, timeout)) { + cond_resched(); + continue; + } + prepare_to_wait(&ctx->sqo_wait, &wait, TASK_INTERRUPTIBLE); |