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From: Christoph Hellwig <hch@lst.de>
To: Ilya Dryomov <idryomov@gmail.com>
Cc: Roman Penyaev <rpenyaev@suse.de>, Jens Axboe <axboe@kernel.dk>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	linux-aio@kvack.org, linux-block <linux-block@vger.kernel.org>,
	linux-arch@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
	jmoyer@redhat.com, avi@scylladb.com,
	linux-block-owner@vger.kernel.org
Subject: Re: [PATCHSET v2] io_uring IO interface
Date: Fri, 11 Jan 2019 17:21:43 +0100	[thread overview]
Message-ID: <20190111162143.GA14914@lst.de> (raw)
In-Reply-To: <CAOi1vP9B7Z5jm4vcLux8eOvixgWmC7V=zKBzGnOOJHYO1AhVwA@mail.gmail.com>

On Fri, Jan 11, 2019 at 05:11:57PM +0100, Ilya Dryomov wrote:
> I think you can use the new IOCB_CMD_POLL from Christoph and avoid
> epoll_wait() in favor of aio/io_uring interface, at least in new high
> performance applications.  Reaping events entirely in userspace (i.e.
> performing io_getevents() without entering the kernel) has been
> possible for a long time even with the existing aio interface.

For io_uring we can reuse the IOCB_CMD_POLL concept, but we'd have to
add a new cancel command, as the uring right now doesn't support
cancelation.  But I'd rather make that command a new opcode instead
of a separate syscall, which would lead to a nicer design.

A prototype for this should be fairly easy, I'd just want someone
to actually use it for real life testing, like ScyllaDB does for
IOCB_CMD_POLL.

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WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Ilya Dryomov <idryomov@gmail.com>
Cc: Roman Penyaev <rpenyaev@suse.de>, Jens Axboe <axboe@kernel.dk>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	linux-aio@kvack.org, linux-block <linux-block@vger.kernel.org>,
	linux-arch@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
	jmoyer@redhat.com, avi@scylladb.com,
	linux-block-owner@vger.kernel.org
Subject: Re: [PATCHSET v2] io_uring IO interface
Date: Fri, 11 Jan 2019 17:21:43 +0100	[thread overview]
Message-ID: <20190111162143.GA14914@lst.de> (raw)
Message-ID: <20190111162143.yQI1dJDhL0Uj4GTq-AmEtdwyOnZsYAIH4ejvO_fQeSc@z> (raw)
In-Reply-To: <CAOi1vP9B7Z5jm4vcLux8eOvixgWmC7V=zKBzGnOOJHYO1AhVwA@mail.gmail.com>

On Fri, Jan 11, 2019 at 05:11:57PM +0100, Ilya Dryomov wrote:
> I think you can use the new IOCB_CMD_POLL from Christoph and avoid
> epoll_wait() in favor of aio/io_uring interface, at least in new high
> performance applications.  Reaping events entirely in userspace (i.e.
> performing io_getevents() without entering the kernel) has been
> possible for a long time even with the existing aio interface.

For io_uring we can reuse the IOCB_CMD_POLL concept, but we'd have to
add a new cancel command, as the uring right now doesn't support
cancelation.  But I'd rather make that command a new opcode instead
of a separate syscall, which would lead to a nicer design.

A prototype for this should be fairly easy, I'd just want someone
to actually use it for real life testing, like ScyllaDB does for
IOCB_CMD_POLL.

  parent reply	other threads:[~2019-01-11 16:21 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-10  2:43 [PATCHSET v2] io_uring IO interface Jens Axboe
2019-01-10  2:43 ` Jens Axboe
2019-01-10  2:43 ` [PATCH 01/15] fs: add an iopoll method to struct file_operations Jens Axboe
2019-01-10  2:43   ` Jens Axboe
2019-01-10  2:43 ` [PATCH 02/15] block: wire up block device iopoll method Jens Axboe
2019-01-10  2:43   ` Jens Axboe
2019-01-10  2:43 ` [PATCH 03/15] block: add bio_set_polled() helper Jens Axboe
2019-01-10  2:43   ` Jens Axboe
2019-01-10  2:43 ` [PATCH 04/15] iomap: wire up the iopoll method Jens Axboe
2019-01-10  2:43   ` Jens Axboe
2019-01-10  2:43 ` [PATCH 05/15] Add io_uring IO interface Jens Axboe
2019-01-10  2:43   ` Jens Axboe
2019-01-11 18:19   ` Martin K. Petersen
2019-01-11 18:19     ` Martin K. Petersen
2019-01-11 18:34     ` Jens Axboe
2019-01-11 18:34       ` Jens Axboe
2019-01-13 16:22       ` Jens Axboe
2019-01-13 16:22         ` Jens Axboe
2019-01-15 17:31         ` Martin K. Petersen
2019-01-15 17:31           ` Martin K. Petersen
2019-01-10  2:43 ` [PATCH 06/15] io_uring: support for IO polling Jens Axboe
2019-01-10  2:43   ` Jens Axboe
2019-01-10  2:43 ` [PATCH 07/15] io_uring: add submission side request cache Jens Axboe
2019-01-10  2:43   ` Jens Axboe
2019-01-10  2:43 ` [PATCH 08/15] fs: add fget_many() and fput_many() Jens Axboe
2019-01-10  2:43   ` Jens Axboe
2019-01-10  2:43 ` [PATCH 09/15] io_uring: use fget/fput_many() for file references Jens Axboe
2019-01-10  2:43   ` Jens Axboe
2019-01-10  2:43 ` [PATCH 10/15] io_uring: batch io_kiocb allocation Jens Axboe
2019-01-10  2:43   ` Jens Axboe
2019-01-10  2:44 ` [PATCH 11/15] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2019-01-10  2:44   ` Jens Axboe
2019-01-10  2:44 ` [PATCH 12/15] io_uring: add support for pre-mapped user IO buffers Jens Axboe
2019-01-10  2:44   ` Jens Axboe
2019-01-10  2:44 ` [PATCH 13/15] io_uring: support kernel side submission Jens Axboe
2019-01-10  2:44   ` Jens Axboe
2019-01-10  2:44 ` [PATCH 14/15] io_uring: add submission polling Jens Axboe
2019-01-10  2:44   ` Jens Axboe
2019-01-10  2:44 ` [PATCH 15/15] io_uring: add io_uring_event cache hit information Jens Axboe
2019-01-10  2:44   ` Jens Axboe
2019-01-10 23:12   ` Jeff Moyer
2019-01-10 23:12     ` Jeff Moyer
2019-01-10 23:47     ` Jens Axboe
2019-01-10 23:47       ` Jens Axboe
2019-01-11  9:46 ` [PATCHSET v2] io_uring IO interface Roman Penyaev
2019-01-11  9:46   ` Roman Penyaev
2019-01-11 16:11   ` Ilya Dryomov
2019-01-11 16:11     ` Ilya Dryomov
2019-01-11 16:21     ` Christoph Hellwig [this message]
2019-01-11 16:21       ` Christoph Hellwig
2019-01-11 16:39     ` Roman Penyaev
2019-01-11 16:39       ` Roman Penyaev
2019-01-11 18:05   ` Jens Axboe
2019-01-11 18:05     ` Jens Axboe

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