On Thu, Mar 15, 2007 at 05:05:13PM +1100, Con Kolivas wrote: > On Thursday 15 March 2007 13:31, Siddha, Suresh B wrote: > > Just to see the % increase in number of context switches, I ran 8 infinite > > loops (simple while(1); 's) and with 2.6.21-rc3 I see ~70 context switches > > every second, whereas with RSDL I see ~530 context switches. > > Thanks. If it's just that then scaling rr interval with cpus somewhat would > help. If you could, the following patch just to test might confirm that. > -#define RR_INTERVAL ((6 * HZ / 1001) + 1) > +#define RR_INTERVAL ((12 * HZ / 1001) + 1)
Context switches now are ~370 per second. Still much above the regular ~70 we see in the mainline. why do you say the rr_interval needs to be scaled with cpus? The basic point in RSDL is, if we have more than one same priority task on a single logic cpu, context switch happens every RR_INTERVAL (6 or 12 msec) whereas in mainline it happens every 100 msec. We need to minimize these context switches. thanks, suresh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
