[PATCH v3 0/2] sched: Queue task on wakelist in the same llc if the wakee cpu is idle

From: Tianchen Ding <dtcccc@linux.alibaba.com>
To: Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
	Daniel Bristot de Oliveira <bristot@redhat.com>,
	Valentin Schneider <vschneid@redhat.com>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH v3 0/2] sched: Queue task on wakelist in the same llc if the wakee cpu is idle
Date: Thu,  2 Jun 2022 12:06:43 +0800	[thread overview]
Message-ID: <20220602040645.275555-1-dtcccc@linux.alibaba.com> (raw)

Wakelist can help avoid cache bouncing and offload the overhead of waker
cpu. So far, using wakelist within the same llc only happens on
WF_ON_CPU, and this limitation could be removed to further improve
wakeup performance. The result of Unixbench Pipe-based Context Switching
can be improved up to ~10%.

v3:
Add a patch to fix the check of nr_running.
After that, we can remove WF_ON_CPU to achieve the same purpose.
Thank Valentin and Mel.

v2: https://lore.kernel.org/all/20220527090544.527411-1-dtcccc@linux.alibaba.com/
Modify commit log to describe key point in detail.
Add more benchmark results on more archs.

v1: https://lore.kernel.org/all/20220513062427.2375743-1-dtcccc@linux.alibaba.com/

Tianchen Ding (2):
  sched: Fix the check of nr_running at queue wakelist
  sched: Remove the limitation of WF_ON_CPU on wakelist if wakee cpu is
    idle

 kernel/sched/core.c  | 27 ++++++++++++++++-----------
 kernel/sched/sched.h |  1 -
 2 files changed, 16 insertions(+), 12 deletions(-)

-- 
2.27.0