i changed the TIMESLICE defined in the sched.c 109 /* 110 * These are the 'tuning knobs' of the scheduler: 111 * 112 * default timeslice is 100 msecs (used only for SCHED_RR tasks). 113 * Timeslices get refilled after they expire. 114 */ 115 #define DEF_TIMESLICE (20 * HZ / 1000)
I compiled and installed the modified kernel, but when i looked at the , i get a different number root@elm:~# cat /proc/sys/kernel/sched_rt_period_us 1000000 Xin On Mon, Aug 20, 2012 at 5:16 PM, Namhyung Kim <namhy...@kernel.org> wrote: > On Mon, 20 Aug 2012 07:51:52 -0700, Xin Tong wrote: >> On Sun, Aug 19, 2012 at 10:54 PM, Mike Galbraith <efa...@gmx.de> wrote: >>> On Sun, 2012-08-19 at 11:58 -0700, Xin Tong wrote: >>>> I have 2 questions about linux 2.6 x86_64 scheduler. >>>> >>>> 1. is the default scheduling algorithm SCHED_NORMAL in linux ? >>> >>> Yes. >> Is there any document describing what the sched_normal is ? it is more >> difficult than SCHED_RR to infer its meaning just based on its name ? >>> >>>> 2. how do i change the time slice in linux source code ? >>> >>> You shouldn't need to. You can tune "slice" by adjusting >>> sched_latency_ns and sched_min_granularity_ns, but note that "slice" is >>> not a fixed quantum. Also note that CFS preemption decisions are based >>> upon instantaneous state. A task may have received a full (variable) >>> "slice" of CPU time, but preemption will be triggered only if a more >>> deserving task is available, so a "slice" is not the "max uninterrupted >>> CPU time" that you may expect it to be.. but it is somewhat similar. >>> >>> -Mike >>> >> This can be done without recompiling and reinstalling the kernel ? >> maybe one simply needs to write to a device file under /dev ? > > You can find those files under /proc/sys/kernel/. > > Thanks, > Namhyung -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
