gpsd-dev
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [gpsd-dev] Linux kernel bug in 3:12, low_latency on serial ports is


From: Beat Bolli
Subject: Re: [gpsd-dev] Linux kernel bug in 3:12, low_latency on serial ports is broken
Date: Thu, 20 Feb 2014 12:14:38 +0100
User-agent: Roundcube Webmail/0.7.2

Hi Hal

I had reported this to linux-serial: http://marc.info/?t=139125913700001&r=1&w=2

I could not make sense of the replies, however.

serial.c does not mention "low-latency" at all. Is the port->low_latency flag set by
"session->ttyset.c_cc[VMIN] = 1;" in serial.c:494?

Regards,
Beat

On 2014-02-20 09:31, Hal Murray wrote:
Just a heads-up in case you hit this, or want to avoid it.

The symptom is BUG: scheduling while atomic
  https://bugzilla.redhat.com/show_bug.cgi?id=1065087

The discussion at
  https://lkml.org/lkml/2014/2/18/77
confirms that it's the low-latency path that is buggy.

My setup works fine under low load, but hits the BUG when I do
something like
compile the ntp package.

3.11 works fine. (for me) There was major work in the serial area for 3.12

I'll send an update when/if it gets fixed.

--
mail: echo '<address@hidden>' | tr -d '[A-S]'
pgp: 0x506A903A; 49D5 794A EA77 F907 764F  D89E 304B 93CF 506A 903A
gsm: 4.7.7.6.0.7.7.9.7.1.4.e164.arpa
icbm: 47.0452 N, 7.2715 E
http: drbeat.li

"It takes love over gold, and mind over matter" -- Dire Straits



reply via email to

[Prev in Thread] Current Thread [Next in Thread]