Hi, v2 of the RFC set implementing frequency/cpu invariance and OPP selection for SCHED_DEADLINE [1]. The set is based on mainline as of today (ae64f9bd1d36).
Patches high level description: o [01-02]/08 add the necessary links to start accounting DEADLINE contribution to OPP selection o 03/08 it's a temporary solution to make possible (on ARM) to change frequency for DEADLINE tasks (that would possibly delay the SCHED_FIFO worker kthread); proper solution would be to be able to issue frequency transition from an atomic ctx o [04-05]/08 it's a schedutil change that copes with the fact that DEADLINE doesn't require periodic OPP selection triggering point o [06-07]/08 make arch_scale_{freq,cpu}_capacity() function available on !CONFIG_SMP configurations too o 08/08 implements frequency/cpu invariance for tasks' reservation parameters; which basically means that we implement GRUB-PA [2] Changes w.r.t. RFCv1: - rebase on mainline - return -EINVAL for user trying to use the new flag (Peter) - s/SPECIAL/SUGOV/ in the flag name (several comments from people to find better naming, Steve thinks SUGOV is more greppable than others) - give worker kthread a fake (unused) bandwidth, so that if priority inheritance is triggered we don't BUG_ON on zero runtime - filter out fake bandwidth when computing SCHED_DEADLINE bandwidth (fix by Claudio Scordino) Please have a look. Feedback and comments are, as usual, more than welcome. In case you would like to test this out: https://github.com/jlelli/linux.git upstream/deadline/freq-rfc-v2 Best, - Juri [1] v0: https://lkml.org/lkml/2017/5/23/249 v1: https://lkml.org/lkml/2017/7/5/139 [2] C. Scordino, G. Lipari, A Resource Reservation Algorithm for Power-Aware Scheduling of Periodic and Aperiodic Real-Time Tasks, IEEE Transactions on Computers, December 2006 Juri Lelli (8): sched/cpufreq_schedutil: make use of DEADLINE utilization signal sched/deadline: move cpu frequency selection triggering points sched/cpufreq_schedutil: make worker kthread be SCHED_DEADLINE sched/cpufreq_schedutil: split utilization signals sched/cpufreq_schedutil: always consider all CPUs when deciding next freq sched/sched.h: remove sd arch_scale_freq_capacity parameter sched/sched.h: move arch_scale_{freq,cpu}_capacity outside CONFIG_SMP sched/deadline: make bandwidth enforcement scale-invariant include/linux/arch_topology.h | 2 +- include/linux/sched.h | 1 + include/linux/sched/cpufreq.h | 2 - include/linux/sched/topology.h | 12 ++-- kernel/sched/core.c | 15 ++++- kernel/sched/cpufreq_schedutil.c | 84 +++++++++++++++--------- kernel/sched/deadline.c | 136 ++++++++++++++++++++++++++++----------- kernel/sched/fair.c | 4 +- kernel/sched/sched.h | 53 +++++++++++---- 9 files changed, 217 insertions(+), 92 deletions(-) -- 2.14.3