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Date: Thu, 11 Jul 2013 02:39:00 -0700
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Subject: Re: hacking - aio_sendfile()
From: Adrian Chadd <adrian@freebsd.org>
To: Konstantin Belousov <kostikbel@gmail.com>
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On 11 July 2013 02:36, Konstantin Belousov <kostikbel@gmail.com> wrote:

> No, it is not disk I/O which is problematic there. It is socket I/O
> e.g. wait for the socket buffers lomark in the kern_sendfile() which
> causes unbounded sleep. Look for the sbwait() call, both in the
> kern_sendfile() itself, and in the pru_send methods of the protocols,
> e.g. in sosend_generic(). The wait scope controlled by the other side of
> connection and allow it to completely block the aio subsystem.
>
> Disk I/O is supposed to finish in the finite time.

Even if the destination socket is marked as NONBLOCK?


-adrian