From: Jens Axboe <axboe@kernel.dk>
To: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
linux-block@vger.kernel.org, linux-arch@vger.kernel.org
Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com,
Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 16/16] io_uring: add io_uring_event cache hit information
Date: Tue, 8 Jan 2019 09:56:45 -0700 [thread overview]
Message-ID: <20190108165645.19311-17-axboe@kernel.dk> (raw)
In-Reply-To: <20190108165645.19311-1-axboe@kernel.dk>
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).
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 6 +++++-
include/uapi/linux/io_uring.h | 5 +++++
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 6c10841e4342..50b9cfa8c861 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -524,12 +524,16 @@ static void io_fill_cq_error(struct io_ring_ctx *ctx, unsigned ki_index,
static void io_complete_scqring_rw(struct kiocb *kiocb, long res, long res2)
{
struct io_kiocb *iocb = container_of(kiocb, struct io_kiocb, rw);
+ unsigned ev_flags = 0;
kiocb_end_write(kiocb);
fput(kiocb->ki_filp);
- io_complete_scqring(iocb, res, 0);
+ if (res > 0 && test_bit(KIOCB_F_FORCE_NONBLOCK, &iocb->ki_flags))
+ ev_flags = IOEV_FLAG_CACHEHIT;
+
+ io_complete_scqring(iocb, res, ev_flags);
}
static void io_complete_scqring_iopoll(struct kiocb *kiocb, long res, long res2)
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index bd665d38dd97..7dd21126f142 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -56,6 +56,11 @@ struct io_uring_event {
__u32 flags;
};
+/*
+ * io_uring_event->flags
+ */
+#define IOEV_FLAG_CACHEHIT (1 << 0) /* IO did not hit media */
+
/*
* Magic offsets for the application to mmap the data it needs
*/
--
2.17.1
next prev parent reply other threads:[~2019-01-08 16:57 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-08 16:56 [PATCHSET v1] io_uring IO interface Jens Axboe
2019-01-08 16:56 ` [PATCH 01/16] fs: add an iopoll method to struct file_operations Jens Axboe
2019-01-08 16:56 ` [PATCH 02/16] block: wire up block device iopoll method Jens Axboe
2019-01-08 16:56 ` [PATCH 03/16] block: add bio_set_polled() helper Jens Axboe
2019-01-10 9:43 ` Ming Lei
2019-01-10 16:05 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 04/16] iomap: wire up the iopoll method Jens Axboe
2019-01-08 16:56 ` [PATCH 05/16] Add io_uring IO interface Jens Axboe
2019-01-09 12:10 ` Christoph Hellwig
2019-01-09 15:53 ` Jens Axboe
2019-01-09 18:30 ` Christoph Hellwig
2019-01-09 20:07 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 06/16] io_uring: support for IO polling Jens Axboe
2019-01-09 12:11 ` Christoph Hellwig
2019-01-09 15:53 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 07/16] io_uring: add submission side request cache Jens Axboe
2019-01-08 16:56 ` [PATCH 08/16] fs: add fget_many() and fput_many() Jens Axboe
2019-01-08 16:56 ` [PATCH 09/16] io_uring: use fget/fput_many() for file references Jens Axboe
2019-01-08 16:56 ` [PATCH 10/16] io_uring: split kiocb init from allocation Jens Axboe
2019-01-09 12:12 ` Christoph Hellwig
2019-01-09 16:56 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 11/16] io_uring: batch io_kiocb allocation Jens Axboe
2019-01-09 12:13 ` Christoph Hellwig
2019-01-09 16:57 ` Jens Axboe
2019-01-09 19:03 ` Christoph Hellwig
2019-01-09 20:08 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 12/16] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2019-01-08 16:56 ` [PATCH 13/16] io_uring: add support for pre-mapped user IO buffers Jens Axboe
2019-01-09 12:16 ` Christoph Hellwig
2019-01-09 17:06 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 14/16] io_uring: support kernel side submission Jens Axboe
2019-01-09 19:06 ` Christoph Hellwig
2019-01-09 20:49 ` Jens Axboe
2019-01-08 16:56 ` [PATCH 15/16] io_uring: add submission polling Jens Axboe
2019-01-08 16:56 ` Jens Axboe [this message]
2019-01-09 16:00 ` [PATCHSET v1] io_uring IO interface Matthew Wilcox
2019-01-09 16:27 ` Chris Mason
2019-01-12 21:29 [PATCHSET v3] " Jens Axboe
2019-01-12 21:30 ` [PATCH 16/16] io_uring: add io_uring_event cache hit information Jens Axboe
[not found] <20190115025531.13985-1-axboe@kernel.dk>
2019-01-15 2:55 ` Jens Axboe
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