On 10/29/19 11:16 AM, Jackie Liu wrote:
> We didn't use -ERESTARTSYS to tell the application layer to restart the
> system call, but instead return -EINTR. we can set -EINTR directly when
> wakeup by the signal, which can help us save an assignment operation and
> comparison operation.
>
> Signed-off-by: Jackie Liu <liuyun01@xxxxxxxxxx>
Looks good to me.
Reviewed-by: Bob Liu <bob.liu@xxxxxxxxxx>
> ---
> fs/io_uring.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index a30c4f6..63eee7e 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -2878,7 +2878,7 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
> .to_wait = min_events,
> };
> struct io_rings *rings = ctx->rings;
> - int ret;
> + int ret = 0;
>
> if (io_cqring_events(rings) >= min_events)
> return 0;
> @@ -2896,7 +2896,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
> return ret;
> }
>
> - ret = 0;
> iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
> do {
> prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
> @@ -2905,15 +2904,13 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
> break;
> schedule();
> if (signal_pending(current)) {
> - ret = -ERESTARTSYS;
> + ret = -EINTR;
> break;
> }
> } while (1);
> finish_wait(&ctx->wait, &iowq.wq);
>
> - restore_saved_sigmask_unless(ret == -ERESTARTSYS);
> - if (ret == -ERESTARTSYS)
> - ret = -EINTR;
> + restore_saved_sigmask_unless(ret == -EINTR);
>
> return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
> }
>
