From: Jens Axboe axboe@kernel.dk
mainline inclusion from mainline-5.6-rc1 commit 895e2ca0f693c672902191747b548bdc56f0c7de category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA ---------------------------
io-wq assumes that work will complete fast (and not block), so it doesn't create a new worker when work is enqueued, if we already have at least one worker running. This is done on the assumption that if work is running, then it will complete fast.
Add an option to force io-wq to fork a new worker for work queued. This is signaled by setting IO_WQ_WORK_CONCURRENT on the work item. For that case, io-wq will create a new worker, even though workers are already running.
Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: yangerkun yangerkun@huawei.com Reviewed-by: zhangyi (F) yi.zhang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- fs/io-wq.c | 5 ++++- fs/io-wq.h | 1 + 2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/io-wq.c b/fs/io-wq.c index df3d58a02fac..09896c7e4205 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -725,6 +725,7 @@ static bool io_wq_can_queue(struct io_wqe *wqe, struct io_wqe_acct *acct, static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) { struct io_wqe_acct *acct = io_work_get_acct(wqe, work); + int work_flags; unsigned long flags;
/* @@ -739,12 +740,14 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) return; }
+ work_flags = work->flags; spin_lock_irqsave(&wqe->lock, flags); wq_list_add_tail(&work->list, &wqe->work_list); wqe->flags &= ~IO_WQE_FLAG_STALLED; spin_unlock_irqrestore(&wqe->lock, flags);
- if (!atomic_read(&acct->nr_running)) + if ((work_flags & IO_WQ_WORK_CONCURRENT) || + !atomic_read(&acct->nr_running)) io_wqe_wake_worker(wqe, acct); }
diff --git a/fs/io-wq.h b/fs/io-wq.h index 04d60ad38dfc..1cd039af8813 100644 --- a/fs/io-wq.h +++ b/fs/io-wq.h @@ -13,6 +13,7 @@ enum { IO_WQ_WORK_INTERNAL = 64, IO_WQ_WORK_CB = 128, IO_WQ_WORK_NO_CANCEL = 256, + IO_WQ_WORK_CONCURRENT = 512,
IO_WQ_HASH_SHIFT = 24, /* upper 8 bits are used for hash key */ };