diff options
| author | Jens Axboe <axboe@kernel.dk> | 2019-01-09 09:39:42 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-02-24 08:20:54 -0700 |
| commit | c5963bfe3e6f35c0c2ba0af4d390b6408ac8d16d (patch) | |
| tree | 7cab9a3d980b7c7fa7adece0a487080901b05638 | |
| parent | 70c5a3ae277c425a3fae288b3af33707b1e0c956 (diff) | |
io_uring: add io_uring_event cache hit informationio_uring-20190224
Add hint on whether a read was served out of the page cache, or if it
hit media. This is useful for buffered async IO, O_DIRECT reads would
never have this set (for obvious reasons).
If the read hit page cache, cqe->flags will have IOCQE_FLAG_CACHEHIT
set.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/io_uring.c | 7 | ||||
| -rw-r--r-- | include/uapi/linux/io_uring.h | 5 |
2 files changed, 11 insertions, 1 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 6285684244c6..d963f96b8bf5 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -611,11 +611,16 @@ static void io_fput(struct io_kiocb *req) static void io_complete_rw(struct kiocb *kiocb, long res, long res2) { struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw); + unsigned ev_flags = 0; kiocb_end_write(kiocb); io_fput(req); - io_cqring_add_event(req->ctx, req->user_data, res, 0); + + if (res > 0 && (req->flags & REQ_F_FORCE_NONBLOCK)) + ev_flags = IOCQE_FLAG_CACHEHIT; + + io_cqring_add_event(req->ctx, req->user_data, res, ev_flags); io_free_req(req); } diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index e23408692118..24906e99fdc7 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -70,6 +70,11 @@ struct io_uring_cqe { }; /* + * io_uring_event->flags + */ +#define IOCQE_FLAG_CACHEHIT (1U << 0) /* IO did not hit media */ + +/* * Magic offsets for the application to mmap the data it needs */ #define IORING_OFF_SQ_RING 0ULL |