Re: aio poll and a new in-kernel poll API V13

From: Al Viro
Date: Fri May 25 2018 - 20:11:27 EST


On Wed, May 23, 2018 at 09:19:49PM +0200, Christoph Hellwig wrote:
> Hi all,
>
> this series adds support for the IOCB_CMD_POLL operation to poll for the
> readyness of file descriptors using the aio subsystem. The API is based
> on patches that existed in RHAS2.1 and RHEL3, which means it already is
> supported by libaio. To implement the poll support efficiently new
> methods to poll are introduced in struct file_operations: get_poll_head
> and poll_mask. The first one returns a wait_queue_head to wait on
> (lifetime is bound by the file), and the second does a non-blocking
> check for the POLL* events. This allows aio poll to work without
> any additional context switches, unlike epoll.
>
> This series sits on top of the aio-fsync series that also includes
> support for io_pgetevents.

OK, I can live with that, except for one problem - the first patch shouldn't
be sitting on top of arseloads of next window fodder.

Please, rebase the rest of the series on top of merge of vfs.git#fixes
(4faa99965e02) with your aio-fsync.4 and tell me what to pull.