Re: pty FIONREAD returning zero breaks emacs in 3.11rc3

From: Peter Hurley
Date: Mon Aug 12 2013 - 21:43:52 EST


On 08/09/2013 05:11 PM, Andi Kleen wrote:

When I run emacs over ssh terminal (no X) on 3.11-rc3 it often ignores key
strokes. I first thought the system was busy or so, but when
stracing the emacs it was not blocked.

Andi,

More information might help me narrow this down since I can't
reproduce this.

Is the ssh session remote?
Can you reproduce this on a local ssh session?
What version of emacs is this? Is it the nox flavor?
What distribution/version?
What platform?

Here's a typical sequence. select/SIGIO wakes it up, but then
FIONREAD returns 0.

I'm not fully sure when it started.

In the 3.11 cycle? or could have started back on 3.9 or earlier?

Could you try to reproduce this on linux-next?

It does not happen all the time, but is quite frequent.

ioctl(3, FIONREAD, [0]) = 0
pselect6(4, [3], [], NULL, {17, 952336932}, {NULL, 8}) = 1 (in [3], left
{17, 504942810})
--- SIGIO {si_signo=SIGIO, si_code=SI_KERNEL} ---
rt_sigreturn() = 1
ioctl(3, FIONREAD, [0]) = 0
ioctl(3, FIONREAD, [0]) = 0
pselect6(4, [3], [], NULL, {17, 504298807}, {NULL, 8}) = ?
ERESTARTNOHAND (Interrupted by signal)
--- SIGIO {si_signo=SIGIO, si_code=SI_KERNEL} ---
rt_sigreturn() = -1 EINTR (Interrupted system
call)
ioctl(3, FIONREAD, [0]) = 0
pselect6(4, [3], [], NULL, {17, 103972440}, {NULL, 8}) = 1 (in [3], left
{16, 864890560})
--- SIGIO {si_signo=SIGIO, si_code=SI_KERNEL} ---
rt_sigreturn() = 1

Would you please attach the full strace of emacs from this session?

Regards,
Peter Hurley
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