On Tue, 2004-07-13 at 15:33, Wolfgang Grandegger wrote: > On 07/13/2004 02:29 PM Philippe Gerum wrote: > > On Wed, 2004-07-07 at 13:37, Wolfgang Grandegger wrote: > >> Hi, > >> > >> I have now commited a first port of RTAI over ADEOS/ppc to the vesuvio > >> branch. One first observation is, that the latencies and task switch > >> times are almost doubled on slow PowerPC processors (MPC860 at 50 MHz). > > > >> I will give some more information on this port including performance > >> figures later on. > >> > > > > It would be interesting to know if the IRQ latencies are also observable > > using the irq_jitter test (or some adaptation of) from the Adeos distro > > (linux/examples/* IIRC). > > These figures look resonable but I cannot compare them directly with the > pre-ADEOS case. From my point of view, the bigger task switch times and > latencies are simply due to additional code to be processed, which shows > up on slow processors (with little caches, etc.). Are there any figures
I could understand a larger overhead due to processing the pipeline with two stages encurring a preemption (still, it's only about 250ns on a Celeron 1Ghz), but I don't get yet why the task switch time is impacted. > for x86? I will provide some preliminary ones for PPC today or tomorrow. > > Thanks. > > Wolfgang. > > > _______________________________________________ > Rtai-dev mailing list > [EMAIL PROTECTED] > https://mail.gna.org/listinfo/rtai-dev -- Philippe.
