From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: [Bug #14015] pty regressed again, breaking expect and gcc's testsuite Date: Fri, 4 Sep 2009 07:55:30 -1000 (HST) Message-ID: References: <19099.52899.620345.326521@pilspetsen.it.uu.se> <19100.31254.666066.755541@pilspetsen.it.uu.se> <200909012042.59856.rjw@sisk.pl> <19105.5352.28380.230615@pilspetsen.it.uu.se> Mime-Version: 1.0 Return-path: In-Reply-To: Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: TEXT/PLAIN; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Mikael Pettersson Cc: "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Alan Cox , Greg KH , Andrew Morton , OGAWA Hirofumi On Fri, 4 Sep 2009, Linus Torvalds wrote: > > How about something like this? It's way too anal - it says that we can > only write data if there's enough space to always push it all the way to > the receive buffer (including all the data that was already buffered up, > ie the "memory_used" part). But if it finally makes the problem go away, > we have another clue. I forgot to actually include the patch. Duh. And again - UNTESTED. Maybe this makes the buffering _too_ small (the 'memory_used' thing is not really counted in bytes buffered, it's counted in how much buffer space we've allocated) and things break even worse and pty's don't work at all. But I think it might work. Linus --- drivers/char/pty.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/char/pty.c b/drivers/char/pty.c index d083c73..139fa5a 100644 --- a/drivers/char/pty.c +++ b/drivers/char/pty.c @@ -91,7 +91,7 @@ static void pty_unthrottle(struct tty_struct *tty) static int pty_space(struct tty_struct *to) { - int n = 8192 - to->buf.memory_used; + int n = to->receive_room - to->buf.memory_used; if (n < 0) return 0; return n;