From: Milton Miller <miltonm@bga.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@suse.de>
Cc: <linux-kernel@vger.kernel.org>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Stefan Bigler <stefan.bigler@keymile.com>,
Toby Gray <toby.gray@realvnc.com>, Felipe Balbi <balbi@ti.com>
Subject: Re: tty breakage in X (Was: tty vs workqueue oddities)
Date: Fri, 03 Jun 2011 05:23:12 -0500 [thread overview]
Message-ID: <1307096592_10534@mail4.comsite.net> (raw)
[not on list so made up cc list]
On Fri Jun 03 2011 about 05:37:52 EST, Linus wrote:
> On Fri, Jun 3, 2011 at 3:56 PM, Benjamin Herrenschmidt wrote:
> > So I think my theory stands that flush_to_ldisc constantly reschedule
> > itself causing the worker thread to eat all CPU and starve the consumer
> > of the PTY. I won't have time to dig much deeper today nor probably this
> > week-end so I'm sending this email for others who want to look.
>
> Gaah - that commit is total and utter crap.
>
> I *removed* the whole "reschedule the work queue again" crap. It was
> totally wrong. See commit a5660b41af6a.
>
> But then commit b1c43f82c5aa added the crap right back in.
>
> So does it all work if you just remove the broken schedule_work() line
> from flush_to_ldisc?
>
> Otherwise we'll need to just revert it. The commit is clearly totally broken.
Its further broken in that the recieve_buf functions return -ERRORS
but the callers don't check for negative values.
milton
next reply other threads:[~2011-06-03 10:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-03 10:23 Milton Miller [this message]
-- strict thread matches above, loose matches on Subject: below --
2011-06-02 7:17 tty vs workqueue oddities Benjamin Herrenschmidt
2011-06-02 8:37 ` tty breakage in X (Was: tty vs workqueue oddities) Benjamin Herrenschmidt
2011-06-02 9:30 ` Andreas Schwab
2011-06-02 10:07 ` Alan Cox
2011-06-03 0:56 ` Benjamin Herrenschmidt
2011-06-03 6:17 ` Benjamin Herrenschmidt
2011-06-03 6:56 ` Benjamin Herrenschmidt
2011-06-03 9:36 ` Linus Torvalds
2011-06-05 14:37 ` Guillaume Chazarain
2011-06-06 14:24 ` Guillaume Chazarain
2011-06-08 2:44 ` Linus Torvalds
2011-06-08 3:31 ` Linus Torvalds
2011-06-08 8:31 ` Guillaume Chazarain
2011-06-08 8:28 ` Felipe Balbi
2011-06-08 9:04 ` Alan Cox
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