From b2607733c0c67fa4e5d862d29fff0c37159b0110 Mon Sep 17 00:00:00 2001 From: Xiaoguang Wang Date: Wed, 10 Jun 2020 19:41:20 +0800 Subject: [PATCH] io_uring: avoid unnecessary io_wq_work copy for fast poll feature to #28736503 commit 405a5d2b2762f2a9813efdee93274d4e7bf607a1 upstream Basically IORING_OP_POLL_ADD command and async armed poll handlers for regular commands don't touch io_wq_work, so only REQ_F_WORK_INITIALIZED is set, can we do io_wq_work copy and restore. Signed-off-by: Xiaoguang Wang Acked-by: Joseph Qi Signed-off-by: Jens Axboe Signed-off-by: Xiaoguang Wang Acked-by: Joseph Qi --- fs/io_uring.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 0ba1a0f4b7e6..f86351f4e9a9 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4254,7 +4254,8 @@ static void io_async_task_func(struct callback_head *cb) spin_unlock_irq(&ctx->completion_lock); /* restore ->work in case we need to retry again */ - memcpy(&req->work, &apoll->work, sizeof(req->work)); + if (req->flags & REQ_F_WORK_INITIALIZED) + memcpy(&req->work, &apoll->work, sizeof(req->work)); kfree(apoll); if (!canceled) { @@ -4351,7 +4352,8 @@ static bool io_arm_poll_handler(struct io_kiocb *req) return false; req->flags |= REQ_F_POLLED; - memcpy(&apoll->work, &req->work, sizeof(req->work)); + if (req->flags & REQ_F_WORK_INITIALIZED) + memcpy(&apoll->work, &req->work, sizeof(req->work)); had_io = req->io != NULL; get_task_struct(current); @@ -4376,7 +4378,8 @@ static bool io_arm_poll_handler(struct io_kiocb *req) if (!had_io) io_poll_remove_double(req); spin_unlock_irq(&ctx->completion_lock); - memcpy(&req->work, &apoll->work, sizeof(req->work)); + if (req->flags & REQ_F_WORK_INITIALIZED) + memcpy(&req->work, &apoll->work, sizeof(req->work)); kfree(apoll); return false; } @@ -4421,7 +4424,9 @@ static bool io_poll_remove_one(struct io_kiocb *req) * io_req_work_drop_env below when dropping the * final reference. */ - memcpy(&req->work, &apoll->work, sizeof(req->work)); + if (req->flags & REQ_F_WORK_INITIALIZED) + memcpy(&req->work, &apoll->work, + sizeof(req->work)); kfree(apoll); } } -- GitLab