From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frederic Weisbecker Subject: [RFC PATCH 0/6] cpuset: Allow to modify isolcpus through cpuset Date: Wed, 14 Jul 2021 15:54:14 +0200 Message-ID: <20210714135420.69624-1-frederic@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626270868; bh=qo7KUgteHWgNW47PtvyntjuZc5d4R6Q5Gt3N6bWyOgg=; h=From:To:Cc:Subject:Date:From; b=mgmLYjetbD+nFD278pzf58PemKwKBbEln0f5LV64/cJhVlvRpwshWdfc3rZcShJMi AJW8XozOc6wG7qUL3ZNiH0wexMsBmIGNdPHPG1iUGwlGvfgZU8D3xurTy+7eIL9X7B Ur5dETD9ECBThjXubHgzRC/2OjZFSQeK8jiRufcJt5ZcYF0HDVu7w3CHDAlr7y5V5G pjcUia56+zfR28SarXGXbqU7RvoeYJDX5q7DuefA6WF4B/db+TxLE553nC4DmPy2f0 JMvJNT+qoxHZqwxeQUvPEspKvPVQ5BueQxr0xyB1ItaLThRgmzHeYMRRBnxHIYZIRE Jwhq8fisPorXA== List-ID: Content-Type: text/plain; charset="us-ascii" To: LKML Cc: Frederic Weisbecker , Tejun Heo , Peter Zijlstra , Juri Lelli , Alex Belits , Nitesh Lal , Thomas Gleixner , Nicolas Saenz , Christoph Lameter , Marcelo Tosatti , Zefan Li , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org The fact that "isolcpus=" behaviour can't be modified at runtime is an eternal source of discussion and debate opposing a useful feature against a terrible interface. I've long since tried to figure out a proper way to control this at runtime using cpusets, which isn't easy as a boot time single cpumask is difficult to map to a hierarchy of cpusets that can even overlap. The idea here is to map the boot-set isolation behaviour to any cpuset directory whose cpumask is a subset of "isolcpus=". I let you browse for details on the last patch. Note this is still WIP and half-baked, but I figured it's important to validate the interface early. git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git cpuset/isolation HEAD: 6d3dba1115b7ea464febf3763244c783e87c7baf Thanks, Frederic --- Frederic Weisbecker (6): pci: Decouple HK_FLAG_WQ and HK_FLAG_DOMAIN cpumask fetch workqueue: Decouple HK_FLAG_WQ and HK_FLAG_DOMAIN cpumask fetch net: Decouple HK_FLAG_WQ and HK_FLAG_DOMAIN cpumask fetch sched/isolation: Split domain housekeeping mask from the rest sched/isolation: Make HK_FLAG_DOMAIN mutable cpuset: Add cpuset.isolation_mask file drivers/pci/pci-driver.c | 21 ++++++-- include/linux/sched/isolation.h | 4 ++ kernel/cgroup/cpuset.c | 111 ++++++++++++++++++++++++++++++++++++++-- kernel/sched/isolation.c | 73 ++++++++++++++++++++++---- kernel/workqueue.c | 4 +- net/core/net-sysfs.c | 6 +-- 6 files changed, 196 insertions(+), 23 deletions(-)