Re: [uClinux-dev] Interrupt latency on M5272

The rest are found at: http://www.kernel.org/pub/linux/kernel/projects/rt/ I don't know what state they are in, but they seem to be very actively maintained. Thanks for the link ! Is there any description anywhere on what these patches do ? Almost certainly. You might find the authors o

Re: [uClinux-dev] Interrupt latency on M5272

Michael Schnell wrote: > >If you want the best available soft real-time on 2.6.22, there's a few > >patches from various people that aren't in standard kernels. > > > >The only one I know about for 2.6.2x is Ingo Molnar et al's > >RT-preemption patch set, which moves things like interrupts and soft

Re: [uClinux-dev] Interrupt latency on M5272

If you want the best available soft real-time on 2.6.22, there's a few patches from various people that aren't in standard kernels. The only one I know about for 2.6.2x is Ingo Molnar et al's RT-preemption patch set, which moves things like interrupts and soft interrupts into their own process

Re: [uClinux-dev] Interrupt latency on M5272

Xin Xie wrote: > However my concern is more related to the context switch timing (the > user process get scheduled after IRQ happens), the worst case > measurement under the ping flood is the 24mS. Is there any way to > schedule a user process more quickly after IRQ happened under the heavy > syste

Re: [uClinux-dev] Interrupt latency on M5272

We have one event that preferably should be handled 'fast' and Greg already provided a good hint as how to hand-tailor handling of an interrupt. OK, If you use a higher priority interrupt than Linux is aware of and is able to block, and same is enabled to interrupt the Linux based ISRs, you o

RE: [uClinux-dev] Interrupt latency on M5272

, 2007 11:31 PM To: uClinux development list Subject: Re: [uClinux-dev] Interrupt latency on M5272 Linux is not a hard realtime OS ! So no maximum latency can be specified. Even not for ISRs (there is no spec how low at max the interrupt might be disabled). For Linux there is just some _soft_ real

Re: [uClinux-dev] Interrupt latency on M5272

Hi Harry, Harry Gunnarsson wrote: Thanks Greg. Perfect, a pointer in the right direction helps a lot. Just one quick followup; In your opinion, given the 60Mhz clock on our M5272 CPU, does the interrupt latency sound in the right ballpark to you? I can't say I have ever closely looked at the

Re: [uClinux-dev] Interrupt latency on M5272

I am fully aware of the fact that Linux is no RTOS. This uClinux system I am working on now, I wouldn't categorize as hard-real time. If it were, we wouldn't use uClinux. We use uClinux because there is a lot of good usable software available; good network stack, JFFS2 support, NFS support etc. We

Re: [uClinux-dev] Interrupt latency on M5272

Linux is not a hard realtime OS ! So no maximum latency can be specified. Even not for ISRs (there is no spec how low at max the interrupt might be disabled). For Linux there is just some _soft_ realtime spec, meaning that the probability for a delay in lower than a certain value. Kernel 2.4

Re: [uClinux-dev] Interrupt latency on M5272

Thanks Greg. Perfect, a pointer in the right direction helps a lot. Just one quick followup; In your opinion, given the 60Mhz clock on our M5272 CPU, does the interrupt latency sound in the right ballpark to you? Thanks, Harry On Nov 21, 2007 4:04 PM, Greg Ungerer <[EMAIL PROTECTED]> wrote: > Hi

Re: [uClinux-dev] Interrupt latency on M5272

Hi Harry, Harry Gunnarsson wrote: Hi everybody, I am running uClinux on a custom board with the following configuration - 20070131 distro with 2.6.22.6 kernel - M5272 CPU clocked at 60MHz (not 66..) - Compiled with CodeSourcery 4.2-47 - Custom board has serial port, RJ45 ethern

[uClinux-dev] Interrupt latency on M5272

Hi everybody, I am running uClinux on a custom board with the following configuration - 20070131 distro with 2.6.22.6 kernel - M5272 CPU clocked at 60MHz (not 66..) - Compiled with CodeSourcery 4.2-47 - Custom board has serial port, RJ45 ethernet Essentially, our application only has one real-time