From mboxrd@z Thu Jan  1 00:00:00 1970
From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Subject: Re: [Bug #14388] keyboard under X with 2.6.31
Date: Fri, 16 Oct 2009 07:29:41 +0900
Message-ID: <87ljjce1ey.fsf@devron.myhome.or.jp>
References: <56acieJJ2fF.A.nEB.Hzl0KB@chimera>
	<C4F8B19E-F4B4-47F3-AE5B-4581C8E3F3AE@gmail.com>
	<87ljjgfcbu.fsf@spindle.srvr.nix>
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	<4AD3F769.5080405@gmail.com>
	<alpine.LNX.2.01.0910130405200.9297@dyndns.pervalidus.net>
	<4AD437F9.9020708@yahoo.co.uk>
	<alpine.LFD.2.01.0910130745550.3438@localhost.localdomain>
	<4AD4DE4C.4010402@yahoo.co.uk>
	<alpine.LFD.2.01.0910131317360.26777@localhost.localdomain>
	<4AD4F548.2030506@microgate.com>
	<alpine.LFD.2.01.0910131514100.3404@localhost.localdomain>
	<1255478932.19056.24.camel@localhost.localdomain>
	<4AD51D6B.7010509@microgate.com>
	<alpine.LFD.2.01.0910131744590.3404@localhost.localdomain>
	<20091014125846.1a3c8d40@lxorguk.ukuu.org.uk>
	<alpine.LFD.2.01.0910140804180.6146@localhost.localdomain>
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In-Reply-To: <alpine.LFD.2.01.0910151447440.6146@localhost.localdomain> (Linus
	Torvalds's message of "Thu, 15 Oct 2009 14:49:56 -0700 (PDT)")
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To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, Oleg Nesterov <oleg@redhat.com>, Paul Fulghum <paulkf@microgate.com>, Boyan <btanastasov@yahoo.co.uk>, "Rafael J. Wysocki" <rjw@sisk.pl>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Kernel Testers List <kernel-testers@vger.kernel.org>, Dmitry Torokhov <dmitry.torokhov@gmail.com>, Ed Tomlinson <edt@aei.ca>

Linus Torvalds <torvalds@linux-foundation.org> writes:

> On Fri, 16 Oct 2009, OGAWA Hirofumi wrote:
>> 
>> I.e. the following or something,
>> 
>> static inline int input_available_p(struct tty_struct *tty, int amt)
>> {
>> 	int try = 0;
>> 
>> retry:
>> 	if (tty->icanon) {
>> 		if (tty->canon_data)
>> 			return 1;
>> 	} else if (tty->read_cnt >= (amt ? amt : 1))
>> 		return 1;
>> 
>> 	if (!checked) {
>> 		tty_flush_to_ldisc(tty);
>> 		try = 1;
>> 		goto retry;
>> 	}
>> 
>> 	return 0;
>> }
>
> Yeah, we could do that. Especially if we ever see this in any profiles. I 
> doubt we do, but..

Yes.  Or, FWIW, I was thinking to delete schedule_delayed_work() for
n_tty with flag or something at previous time.  I.e. disable background
flush_to_ldisc() by writer for n_tty, only n_tty_read() will check
tty.buf synchronously.

So, with it, unnecessary flush_to_ldisc() is removed completely... Well...

Thanks.
-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>