Re: [rtl] APM alert !!!!
David Schleef ([EMAIL PROTECTED]) wrote: > On Mon, Jun 05, 2000 at 12:34:45PM +0400, Michael Barabanov wrote: > > Linux 2.3.xx kernels allow APM support to be built as a module. > > This feature solves the problem for at least RTL 3.0. > > > > Michael. > > > > > How does compiling as a module help? I normally have APM enabled. I disable it (rmmod apm) when about to run an RTL application. -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
Re: [rtl] APM alert !!!!
On Mon, Jun 05, 2000 at 12:34:45PM +0400, Michael Barabanov wrote: > Linux 2.3.xx kernels allow APM support to be built as a module. > This feature solves the problem for at least RTL 3.0. > > Michael. > How does compiling as a module help? dave... -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
Re: [rtl] APM alert !!!!
Michael Barabanov wrote:
>
> Linux 2.3.xx kernels allow APM support to be built as a module.
> This feature solves the problem for at least RTL 3.0.
>
> Michael.
>
> David Schleef ([EMAIL PROTECTED]) wrote:
> > On Thu, Jun 01, 2000 at 04:37:35PM +0100, Stuart Hughes wrote:
> > > Hi Victor,
> > >
> > > Tried it on RTLinux 2.3/Linux 2.2.14. Exactly the same effect. If you
> > > cat /proc/apm, the jitter jumps out to ~ 7 miliseconds.
> > >
> > > Regards, Stuart.
> > >
> >
I see that you also discovered the missing safe_halt() in acpi.c, while
that macro, defined in system.h, was used in apm.c.
Since you are likely in contact with plain linux "kernellers" that
count, can you tell them that to keep it simple the same macro must be
used wherever is needed, instead of repeating the inlining of the
related __asm__ __volatile__.
RTAI and RTL users must know that this is one of those cases in which
inlined hard "sti"s can do a lot of harm once the kernel is patched for
real time.
Just mate a __cli() to a __asm__ __volatile ("sti") and you are screwed
up.
So if you are using __cli(), for disabling interrupts in Linux, always
mate it with its brother __sti(). Never inline "sti".
Ciao, Paolo.
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Re: [rtl] APM alert !!!!
Linux 2.3.xx kernels allow APM support to be built as a module. This feature solves the problem for at least RTL 3.0. Michael. David Schleef ([EMAIL PROTECTED]) wrote: > On Thu, Jun 01, 2000 at 04:37:35PM +0100, Stuart Hughes wrote: > > Hi Victor, > > > > Tried it on RTLinux 2.3/Linux 2.2.14. Exactly the same effect. If you > > cat /proc/apm, the jitter jumps out to ~ 7 miliseconds. > > > > Regards, Stuart. > > > > > Every so often, a thread comes up in the Linux kernel mailing list about > modifying the kernel to run APM inside a virtual machine, since APM also > causes problems with SMP. There is already other code doing this, such > as (I think) the VESA framebuffer code and BIOS calls on other > architectures. Usually, the thread erupts into a flamewar about the > stupidities involved with running something inside a virtual machine > _inside_ the kernel. > > Supposedly, ACPI will solve these problems, except that a) ACPI doesn't > work on my machine, and b) the user-space ACPI code was developed > independently from the APM code, and thus is incompatible. Go figure. > > > > dave... > > -- [rtl] --- > To unsubscribe: > echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR > echo "unsubscribe rtl " | mail [EMAIL PROTECTED] > --- > For more information on Real-Time Linux see: > http://www.rtlinux.org/rtlinux/ -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
Re: [rtl] APM alert !!!!
On Thu, Jun 01, 2000 at 04:37:35PM +0100, Stuart Hughes wrote: > Hi Victor, > > Tried it on RTLinux 2.3/Linux 2.2.14. Exactly the same effect. If you > cat /proc/apm, the jitter jumps out to ~ 7 miliseconds. > > Regards, Stuart. > Every so often, a thread comes up in the Linux kernel mailing list about modifying the kernel to run APM inside a virtual machine, since APM also causes problems with SMP. There is already other code doing this, such as (I think) the VESA framebuffer code and BIOS calls on other architectures. Usually, the thread erupts into a flamewar about the stupidities involved with running something inside a virtual machine _inside_ the kernel. Supposedly, ACPI will solve these problems, except that a) ACPI doesn't work on my machine, and b) the user-space ACPI code was developed independently from the APM code, and thus is incompatible. Go figure. dave... -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
Re: [rtl] APM alert !!!!
Hi Victor, Tried it on RTLinux 2.3/Linux 2.2.14. Exactly the same effect. If you cat /proc/apm, the jitter jumps out to ~ 7 miliseconds. Regards, Stuart. Stuart Hughes wrote: > > Hi Victor, > > The version was RTAI-1.3 and Linux 2.2.14 on top of a RedHat 6.2, the > machine was an Inspiron 7000 with bios power saving disabled (disk power > down etc) but with APM support in the Linux kernel. I'll be running the > same test on RTLinux 2.3 and post the results. > > Regards, Stuart. > > [EMAIL PROTECTED] wrote: > > > > Stuart: > >What's the version information on this? > > > > On Thu, Jun 01, 2000 at 11:39:29AM +0100, Stuart Hughes wrote: > > > I always knew that APM was bad news for realtime (as it does cli etc), > > > but I was not aware that gettting the APM info from proc was also a > > > disaster. While running some jitter tests that normally give +/- 7usec > > > on a quite machine, I did a cat /proc/apm, this pushed the upper limit > > > to 7milliseconds. So beware, just running a little X helper like xapm > > > (now disapeared from the latest redhat) will cause your realtime to > > > miss-behave. > > > > > > Conclusion: If you have APM enabled at all, beware as your real-time > > > programs can go out to lunch (even things as innocent as plugging in the > > > power cable to your laptop). > > > -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
Re: [rtl] APM alert !!!!
Hi Victor, The version was RTAI-1.3 and Linux 2.2.14 on top of a RedHat 6.2, the machine was an Inspiron 7000 with bios power saving disabled (disk power down etc) but with APM support in the Linux kernel. I'll be running the same test on RTLinux 2.3 and post the results. Regards, Stuart. [EMAIL PROTECTED] wrote: > > Stuart: >What's the version information on this? > > On Thu, Jun 01, 2000 at 11:39:29AM +0100, Stuart Hughes wrote: > > I always knew that APM was bad news for realtime (as it does cli etc), > > but I was not aware that gettting the APM info from proc was also a > > disaster. While running some jitter tests that normally give +/- 7usec > > on a quite machine, I did a cat /proc/apm, this pushed the upper limit > > to 7milliseconds. So beware, just running a little X helper like xapm > > (now disapeared from the latest redhat) will cause your realtime to > > miss-behave. > > > > Conclusion: If you have APM enabled at all, beware as your real-time > > programs can go out to lunch (even things as innocent as plugging in the > > power cable to your laptop). > > > > Regards, Stuart > > -- [rtl] --- > > To unsubscribe: > > echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR > > echo "unsubscribe rtl " | mail [EMAIL PROTECTED] > > --- > > For more information on Real-Time Linux see: > > http://www.rtlinux.org/rtlinux/ > > -- > - > Victor Yodaiken > FSMLabs: www.fsmlabs.com www.rtlinux.com > FSMLabs is a servicemark and a service of > VJY Associates L.L.C, New Mexico. -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
Re: [rtl] APM alert !!!!
Stuart: What's the version information on this? On Thu, Jun 01, 2000 at 11:39:29AM +0100, Stuart Hughes wrote: > I always knew that APM was bad news for realtime (as it does cli etc), > but I was not aware that gettting the APM info from proc was also a > disaster. While running some jitter tests that normally give +/- 7usec > on a quite machine, I did a cat /proc/apm, this pushed the upper limit > to 7milliseconds. So beware, just running a little X helper like xapm > (now disapeared from the latest redhat) will cause your realtime to > miss-behave. > > Conclusion: If you have APM enabled at all, beware as your real-time > programs can go out to lunch (even things as innocent as plugging in the > power cable to your laptop). > > Regards, Stuart > -- [rtl] --- > To unsubscribe: > echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR > echo "unsubscribe rtl " | mail [EMAIL PROTECTED] > --- > For more information on Real-Time Linux see: > http://www.rtlinux.org/rtlinux/ -- - Victor Yodaiken FSMLabs: www.fsmlabs.com www.rtlinux.com FSMLabs is a servicemark and a service of VJY Associates L.L.C, New Mexico. -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
[rtl] APM alert !!!!
I always knew that APM was bad news for realtime (as it does cli etc), but I was not aware that gettting the APM info from proc was also a disaster. While running some jitter tests that normally give +/- 7usec on a quite machine, I did a cat /proc/apm, this pushed the upper limit to 7milliseconds. So beware, just running a little X helper like xapm (now disapeared from the latest redhat) will cause your realtime to miss-behave. Conclusion: If you have APM enabled at all, beware as your real-time programs can go out to lunch (even things as innocent as plugging in the power cable to your laptop). Regards, Stuart -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
