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Date: Mon, 1 Feb 2016 00:02:14 +0100
From: Jilles Tjoelker <jilles@stack.nl>
To: John Baldwin <jhb@freebsd.org>
Cc: arch@freebsd.org
Subject: Re: Refactoring asynchronous I/O
Message-ID: <20160131230214.GA37435@stack.nl>
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On Tue, Jan 26, 2016 at 05:39:03PM -0800, John Baldwin wrote:
> Note that binding the AIO support to a new fileop does mean that the AIO code
> now becomes mandatory (rather than optional).  We could perhaps make the
> system calls continue to be optional if people really need that, but the guts
> of the code will now need to always be in the kernel.

Enabling this by default is OK with me as long as the easy ways to get a
stuck process are at least disabled by default. Currently, a process
gets stuck forever if it has an AIO request from or to a pipe that will
never complete. An AIO daemon should not be allowed to perform an
unbounded sleep such as for a pipe (NFS server should be OK).

-- 
Jilles Tjoelker