19 Oct
2012
19 Oct
'12
3:02 p.m.
Hello all,
My ex-collegues at Alcatel are screaming for help. They want to run
an app (as root, debatable but that's another story) using SCHED_FIFO
threads on an openSuSE 11.4 system.
Using the 'default' kernel (which has CONFIG_PREEMPT not set), this
works. Using the 'desktop' kernel (CONFIG_PREEMPT=y) they get an
EPERM when trying to start a RT thread, even as root.
As I haven't used SuSE for ages, has anyone an idea of what is
happening here ?
TIA,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
19 Oct
19 Oct
3:41 p.m.
On 10/19/2012 03:02 PM, Fons Adriaensen wrote:
Hello all,
My ex-collegues at Alcatel are screaming for help. They want to
run an app (as root, debatable but that's another story) using
SCHED_FIFO threads on an openSuSE 11.4 system.
Using the 'default' kernel (which has CONFIG_PREEMPT not set),
this works. Using the 'desktop' kernel (CONFIG_PREEMPT=y) they get
an EPERM when trying to start a RT thread, even as root.
As I haven't used SuSE for ages, has anyone an idea of what is
happening here ?
I never used openSuse. and "does not work" is too little info for an
educated guess. So just a few shots in the dark:
/proc/sys/kernel/sched_rt_period_us
/proc/sys/kernel/sched_rt_runtime_us
kernel.sched_rt_runtime_us globally limits realtime
scheduling time.
Maybe cgroups are getting in the way? or possibly grsecurity.
Since it works with the vanilla kernel, PAM and
/etc/security/limits.conf etc do not seem to be the cause, but hey: It
could be related to cgroups, sessions and not su'ing properly.
ciao,
robin
6:02 p.m.
2012-10-19 15:02, Fons Adriaensen skrev:
Hello all,
My ex-collegues at Alcatel are screaming for help. They want to run
an app (as root, debatable but that's another story) using SCHED_FIFO
threads on an openSuSE 11.4 system.
Using the 'default' kernel (which has CONFIG_PREEMPT not set), this
works. Using the 'desktop' kernel (CONFIG_PREEMPT=y) they get an
EPERM when trying to start a RT thread, even as root.
As I haven't used SuSE for ages, has anyone an idea of what is
happening here ?
Try with chrt.
On my laptop with opensuse 11.4 with desktop-kernel. I started "top" as
root.
linux-do4z:~ # ps -up `pidof top`
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 15666 0.4 0.0 8848 1300 pts/19 S+ 17:54 0:00 top
linux-do4z:~ # chrt -p `pidof top`
pid 15666's current scheduling policy: SCHED_OTHER
pid 15666's current scheduling priority: 0
linux-do4z:~ # chrt -f -p 20 `pidof top`
linux-do4z:~ # chrt -p `pidof top`
pid 15666's current scheduling policy: SCHED_FIFO
pid 15666's current scheduling priority: 20
check with "chrt -m" for priorities.
regards,
/bengan
20 Oct
20 Oct
7:45 p.m.
On 10/19/2012 03:02 PM, Fons Adriaensen wrote:
Hello all,
My ex-collegues at Alcatel are screaming for help. They want to run
an app (as root, debatable but that's another story) using SCHED_FIFO
threads on an openSuSE 11.4 system.
Using the 'default' kernel (which has CONFIG_PREEMPT not set), this
works. Using the 'desktop' kernel (CONFIG_PREEMPT=y) they get an
EPERM when trying to start a RT thread, even as root.
As I haven't used SuSE for ages, has anyone an idea of what is
happening here ?
TIA,
god's way of telling them oS 11.4 has just been deprecated and will not
receive further mainline support? :)
i'm not sure 11.4 had cgroups enabled already, but if so, then robin is
probably right on the mark.
--
Jörn Nettingsmeier
Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487
Meister für Veranstaltungstechnik (Bühne/Studio)
Tonmeister VDT
http://stackingdwarves.net
11:56 p.m.
On Sat, Oct 20, 2012 at 07:44:07PM +0200, Jörn Nettingsmeier wrote:
god's way of telling them oS 11.4 has just been
deprecated and will
not receive further mainline support? :)
I'm trying to make them use something else (and a lot of other things),
but it's like trying to move the Alps.
i'm not sure 11.4 had cgroups enabled already, but
if so, then robin
is probably right on the mark.
He was. They discovered that disabling AUTOGROUPS allowed them to
run the app. Which probably means that those automatically created
cgroups were not set up correctly. I have AUTOGROUPS enabled and
have been running the same app *as a normal user* for the last two
months.
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
4445
days inactive
4446
days old
linux-audio-dev@lists.linuxaudio.org
4 comments
4 participants
participants (4)
-
Bengt Gördén -
Fons Adriaensen -
Jörn Nettingsmeier -
Robin Gareus