Since, Ubuntu is being run on the kernel, the standard processes of Ubuntu are running in the background. Now, I was just checking out RT_PREEMPT yesterday, and I came across the kernel 2.6.31-9-rt (It is an RT_PREEMPT kernel) in the ubuntu repositories (for ubuntu 9.10). I installed the kernel, and booted into ubuntu using this kernel. Now, I see the results as I had expected - 2 out of the 4 cores running on full load. What could be the problem in my configuration as I am unable to see the same results with the kernel that I configured? Thanks and Regards, Neel Mehta Third year Undergraduate student, Electrical Engineering, IIT Bombay On Thu, Jun 17, 2010 at 10:16 PM, Nivedita Singhvi <niv@xxxxxxxxxx> wrote: > > Neel Mehta wrote: >> >> Hi. I have 2 computers with ubuntu: >> 1. Core 2 Duo - Non realtime linux kernel >> 2. Quad core - Realtime linux kernel >> >> Both of them are using ubuntu. I am running a process that generates 2 >> threads, both of which are continuously processing something. >> 1. On core 2 duo (normal kernel): both the cores are running above 90% load. >> 2. on quad core(realtime kernel): only one core runs above 90%, and >> the other cores are not at such a high load. The core which is on high >> load keeps on alternating among the 4 cores. >> >> So, my question is why doesnt 2 cores run on high load on quad core? >> Is there a problem in multiprocessing in realtime linux kernel? Can >> someone guide me where the source of problem could be? > > I'll start with the obvious - if the same amount of work is > being done, but now on a larger number of cores, the load on > each individual core could reduce (since you don't say what > else is contributing to the load on the system, etc). > > As an example of this class of behavior, look at your irq distribution. > The rotation of the load sounds a lot like it's being driven by > interrupt round-robining, for instance. > > thanks, > Nivedita -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
