Re: 2.6.31-rc5: Reported regressions from 2.6.30

Johannes Weiner
2009-08-03T14:31:08Z

On Sun, Aug 02, 2009 at 03:22:01PM -0700, Linus Torvalds wrote:

> > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=13815
> > Subject : emacs -nw compilation doesn't show the error message
> > Submitter : Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> > Date : 2009-07-23 06:22 (11 days old)
> > First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d945cb9cce20ac7143c2de8d88b187f62db99bdc
>
> Same old pty bug, same fix: commit e043e42bdb.
>
> > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=13813
> > Subject : Hangups in n_tty_read()
> > Submitter : Johannes Weiner <hannes@cmpxchg.org>
> > Date : 2009-07-16 18:48 (18 days old)
> > References : http://marc.info/?l=linux-kernel&m=124777019920579&w=4
>
> Hmm. Worth testing that same fix, although the symptoms here are not
> exactly the same.

Hm, I had no debugging enabled, but I think a silent hang in

pty_write()
tty_flip_buffer_push()
flush_to_ldisc()

can cause the receiving side

tty_read()
n_tty_read()

to wait forever for updates. I haven't looked closely. It seems to
be gone with your latest master in any case.

Hannes