From: Luca Abeni <luca.abeni@santannapisa.it> To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, "Rafael J . Wysocki" <rafael@kernel.org>, Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>, Vincent Guittot <vincent.guittot@linaro.org>, "Paul E . McKenney" <paulmck@linux.ibm.com>, Joel Fernandes <joel@joelfernandes.org>, Quentin Perret <quentin.perret@arm.com>, Luc Van Oostenryck <luc.vanoostenryck@gmail.com>, Morten Rasmussen <morten.rasmussen@arm.com>, Juri Lelli <juri.lelli@redhat.com>, Daniel Bristot de Oliveira <bristot@redhat.com>, Patrick Bellasi <patrick.bellasi@arm.com>, Tommaso Cucinotta <tommaso.cucinotta@santannapisa.it>, luca abeni <luca.abeni@santannapisa.it> Subject: [RFC PATCH 0/6] Capacity awareness for SCHED_DEADLINE Date: Mon, 6 May 2019 06:48:30 +0200 Message-ID: <20190506044836.2914-1-luca.abeni@santannapisa.it> (raw) From: luca abeni <luca.abeni@santannapisa.it> The SCHED_DEADLINE scheduling policy currently has some issues with asymmetric CPU capacity architectures (such as ARM big.LITTLE). In particular, the admission control mechanism does not work correctly (because it considers all cores to have the same speed of the fastest core), and the scheduler does not consider the cores' speed when migrating tasks. This patchset fixes the issues by explicitly considering the cores' capacities in the admission control mechanism and in tasks' migration. In particular, the scheduler is improved so that "heavyweight tasks" (processes or threads having a runtime that on LITTLE cores becomes larger than the relative deadline) are scheduled on big cores. This allows respecting deadlines that are missed by the current scheduler. Moreover, the migration logic is modified so that "lightweight tasks" (processes or threads having a runtime that on LITTLE cores is still smaller than the relative deadline) are scheduled on LITTLE cores when possible. This allows saving some energy without missing deadlines. luca abeni (6): sched/dl: Improve deadline admission control for asymmetric CPU capacities sched/dl: Capacity-aware migrations sched/dl: Try better placement even for deadline tasks that do not block sched/dl: Improve capacity-aware wakeup sched/dl: If the task does not fit anywhere, select the fastest core sched/dl: Try not to select a too fast core drivers/base/arch_topology.c | 1 + include/linux/sched.h | 1 + include/linux/sched/topology.h | 3 ++ kernel/sched/core.c | 2 + kernel/sched/cpudeadline.c | 53 ++++++++++++++++++++++-- kernel/sched/deadline.c | 76 ++++++++++++++++++++++++++++------ kernel/sched/sched.h | 16 +++++-- kernel/sched/topology.c | 9 ++++ 8 files changed, 143 insertions(+), 18 deletions(-) -- 2.20.1
next reply index Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-05-06 4:48 Luca Abeni [this message] 2019-05-06 4:48 ` [RFC PATCH 1/6] sched/dl: Improve deadline admission control for asymmetric CPU capacities Luca Abeni 2019-05-07 13:48 ` Quentin Perret 2019-05-07 13:55 ` Vincent Guittot 2019-05-07 14:02 ` Quentin Perret 2019-05-07 14:25 ` luca abeni 2019-05-07 14:31 ` Quentin Perret 2019-05-07 14:43 ` luca abeni 2019-07-08 11:22 ` Dietmar Eggemann 2019-07-08 15:05 ` Quentin Perret 2019-06-18 16:41 ` Alessio Balsini 2019-05-06 4:48 ` [RFC PATCH 2/6] sched/dl: Capacity-aware migrations Luca Abeni 2019-05-07 13:35 ` Quentin Perret 2019-05-07 14:17 ` luca abeni 2019-05-07 15:04 ` Quentin Perret 2019-05-07 14:10 ` Quentin Perret 2019-05-07 14:41 ` luca abeni 2019-05-07 15:02 ` Quentin Perret 2019-05-08 8:04 ` Juri Lelli 2019-05-08 8:17 ` luca abeni 2019-07-04 12:05 ` Dietmar Eggemann 2019-07-08 7:41 ` luca abeni 2019-07-08 10:41 ` Dietmar Eggemann 2019-05-06 4:48 ` [RFC PATCH 3/6] sched/dl: Try better placement even for deadline tasks that do not block Luca Abeni 2019-05-07 14:13 ` Quentin Perret 2019-05-07 16:00 ` Morten Rasmussen 2019-05-08 8:01 ` Juri Lelli 2019-05-08 8:14 ` luca abeni 2019-05-08 9:22 ` Juri Lelli 2019-07-08 13:55 ` Peter Zijlstra 2019-07-09 13:24 ` luca abeni 2019-07-09 13:42 ` Peter Zijlstra 2019-07-11 11:17 ` Dietmar Eggemann 2019-07-11 12:00 ` Peter Zijlstra 2019-07-11 15:33 ` Dietmar Eggemann 2019-07-09 14:44 ` Dietmar Eggemann 2019-05-06 4:48 ` [RFC PATCH 4/6] sched/dl: Improve capacity-aware wakeup Luca Abeni 2019-05-08 9:08 ` Juri Lelli 2019-05-08 9:24 ` luca abeni 2019-05-08 12:05 ` Juri Lelli 2019-05-08 12:47 ` luca abeni 2019-05-08 13:10 ` Juri Lelli 2019-05-08 14:12 ` luca abeni 2019-05-06 4:48 ` [RFC PATCH 5/6] sched/dl: If the task does not fit anywhere, select the fastest core Luca Abeni 2019-05-06 4:48 ` [RFC PATCH 6/6] sched/dl: Try not to select a too fast core Luca Abeni 2019-05-07 15:57 ` Quentin Perret 2019-05-08 6:26 ` luca abeni 2019-05-09 13:46 ` Quentin Perret
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