Message-ID: <486E9366.2090901@skyrush.com>
Date: Fri, 04 Jul 2008 15:17:26 -0600
From: Joe Peterson <joe@skyrush.com>
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To: Alan Cox <alan@lxorguk.ukuu.org.uk>
CC: Elias Oltmanns <eo@nebensachen.de>,
       =?ISO-8859-1?Q?T=F6r=F6k_Edwin?= <edwintorok@gmail.com>,
       Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: Ctrl+C doesn't interrupt process waiting for I/O
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Alan Cox wrote:
>> disk activity process over each time it completed), it always broke out
>> after one ^C - one time took an extra second or two.  Note that I did
>> not run latencytop (did not have it compiled in my kernel) - if that is
>> required for the test, let me know, but I assume it is just for
>> gathering info when the issue occurs.
> 
> I really don't think this is tty related looking at the code involved and
> also the lack of actual measurements presented. More likely scheduler and
> VM related changes.

Alan, many thanks for your assessment - it's greatly appreciated.  Now
that I've looked into it, the only peculiar thing I see is the redundant
flush_buffer call.  Do you think that should be removed anyway?  It
seems that the following two calls do the same thing in n_tty.c:

		n_tty_flush_buffer(tty);
		tty_driver_flush_buffer(tty);

If this looks redundant, let me know, and I can submit a patch to just
call n_tty_flush_buffer(tty).

					-Thanks, Joe
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