From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michael Guntsche <mike@it-loops.com>, linux-kernel@vger.kernel.org
Subject: Re: BUG: scheduling while atomic
Date: Mon, 6 Jul 2009 11:00:14 +0100 [thread overview]
Message-ID: <20090706110014.5cbcc2d7@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <20090706074333.GA17276@gondor.apana.org.au>
> So what see here is that on xmit from the network,
> PPP will call pty_write from BH context which eventually leads
> to tty_throttle and the sleep.
That would I fit the symptoms and also explain why some broken versions
of the USB code on embedded devices also exploded with PPP over USB links.
Not however at all easy to fix as it only ever worked in the past on the
"close both eyes, pray and jump" principle of locking.
Added to the todo list for later this week. The pty layer has all sorts
of magic hackery to allow it to call back and forth without going via
internal tty buffering like normal hardware. That may have to die as it
causes other horrible problems too.
Alan
next prev parent reply other threads:[~2009-07-06 9:59 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-27 11:10 Michael Guntsche
2009-06-27 13:06 ` Alan Cox
2009-06-27 16:07 ` Michael Guntsche
2009-07-06 7:43 ` Herbert Xu
2009-07-06 8:31 ` Herbert Xu
2009-07-06 15:28 ` Michael Guntsche
2009-07-06 15:32 ` Alan Cox
2009-07-06 17:17 ` Alan Cox
2009-07-06 18:07 ` Michael Guntsche
2009-07-06 18:18 ` Alan Cox
2009-07-06 18:37 ` Michael Guntsche
2009-07-06 10:00 ` Alan Cox [this message]
-- strict thread matches above, loose matches on Subject: below --
2012-02-13 8:08 Florian Tobias Schandinat
2010-08-27 7:59 Sergey Senozhatsky
2010-08-27 19:02 ` Rafael J. Wysocki
2010-08-28 6:42 ` Pavel Machek
2010-08-30 7:29 ` Sergey Senozhatsky
2010-08-30 10:04 ` Sergey Senozhatsky
2009-06-19 18:15 Sergey Senozhatsky
2009-06-20 17:43 ` Rabin Vincent
2009-06-20 18:54 ` Sergey Senozhatsky
2009-06-22 9:04 ` Alan Cox
2009-06-22 9:57 ` Alan Cox
2009-06-22 11:33 ` Sergey Senozhatsky
2009-06-22 12:36 ` Alan Cox
2009-06-22 13:59 ` Sergey Senozhatsky
2009-07-06 7:55 ` Herbert Xu
2006-12-08 15:47 Christian
2006-06-02 9:39 fonseka
2006-06-02 12:37 ` Roger Luethi
2006-06-02 14:07 ` fonseka
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