Yuyang Du <yuyang...@intel.com> writes: > On Fri, Sep 11, 2015 at 10:05:53AM -0700, bseg...@google.com wrote: >> >> SCHED_LOAD_RESOLUTION and the non-SLR part of SCHED_LOAD_SHIFT are not >> required to be the same value and should not be conflated. > >> In particular, since cgroups are on the same timeline as tasks and their >> shares are not scaled by SCHED_LOAD_SHIFT in any way (but are scaled so >> that SCHED_LOAD_RESOLUTION is invisible), changing that part of >> SCHED_LOAD_SHIFT would cause issues, since things can assume that nice-0 >> = 1024. However changing SCHED_LOAD_RESOLUTION would be fine, as that is >> an internal value to the kernel. >> >> In addition, changing the non-SLR part of SCHED_LOAD_SHIFT would require >> recomputing all of prio_to_weight/wmult for the new NICE_0_LOAD. > > Not fully looked into the concerns, but the new SCHED_RESOLUTION_SHIFT > is intended to formalize all the integer metrics that need better resolution. > It is not special to any metric, so actually it is to de-conflate whoever is > conflated.
It conflates the userspace-invisible SCHED_LOAD_RESOLUTION with the userspace-visible value of scale_load_down(NICE_0_LOAD). Increasing SCHED_LOAD_RESOLUTION must not change scale_load_down(NICE_0_LOAD). -- 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/
