From mboxrd@z Thu Jan 1 00:00:00 1970 From: Waiman Long Subject: Re: [PATCH v10 6/9] cpuset: Make generate_sched_domains() recognize isolated_cpus Date: Mon, 18 Jun 2018 22:44:41 +0800 Message-ID: <64a0ea0d-c873-f53e-654e-1dd60f833478@redhat.com> References: <1529295249-5207-1-git-send-email-longman@redhat.com> <1529295249-5207-7-git-send-email-longman@redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1529295249-5207-7-git-send-email-longman@redhat.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Tejun Heo , Li Zefan , Johannes Weiner , Peter Zijlstra , Ingo Molnar Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com, luto@amacapital.net, Mike Galbraith , torvalds@linux-foundation.org, Roman Gushchin , Juri Lelli , Patrick Bellasi On 06/18/2018 12:14 PM, Waiman Long wrote: > The generate_sched_domains() function and the hotplug code are modified > to make them use the newly introduced isolated_cpus mask for schedule > domains generation. > > Signed-off-by: Waiman Long > --- > kernel/cgroup/cpuset.c | 24 ++++++++++++++++++++---- > 1 file changed, 20 insertions(+), 4 deletions(-) > > diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c > index cfc9b7b..5ee4239 100644 > --- a/kernel/cgroup/cpuset.c > +++ b/kernel/cgroup/cpuset.c > @@ -672,13 +672,14 @@ static int generate_sched_domains(cpumask_var_t **domains, > int ndoms = 0; /* number of sched domains in result */ > int nslot; /* next empty doms[] struct cpumask slot */ > struct cgroup_subsys_state *pos_css; > + bool root_load_balance = is_sched_load_balance(&top_cpuset); > > doms = NULL; > dattr = NULL; > csa = NULL; > > /* Special case for the 99% of systems with one, full, sched domain */ > - if (is_sched_load_balance(&top_cpuset)) { > + if (root_load_balance && !top_cpuset.isolation_count) { > ndoms = 1; > doms = alloc_sched_domains(ndoms); > if (!doms) > @@ -701,6 +702,8 @@ static int generate_sched_domains(cpumask_var_t **domains, > csn = 0; > > rcu_read_lock(); > + if (root_load_balance) > + csa[csn++] = &top_cpuset; > cpuset_for_each_descendant_pre(cp, pos_css, &top_cpuset) { > if (cp == &top_cpuset) > continue; > @@ -711,6 +714,9 @@ static int generate_sched_domains(cpumask_var_t **domains, > * parent's cpus, so just skip them, and then we call > * update_domain_attr_tree() to calc relax_domain_level of > * the corresponding sched domain. > + * > + * If root is load-balancing, we can skip @cp if it > + * is a subset of the root's effective_cpus. > */ > if (!cpumask_empty(cp->cpus_allowed) && > !(is_sched_load_balance(cp) && > @@ -718,11 +724,16 @@ static int generate_sched_domains(cpumask_var_t **domains, > housekeeping_cpumask(HK_FLAG_DOMAIN)))) > continue; > > + if (root_load_balance && > + cpumask_subset(cp->cpus_allowed, top_cpuset.effective_cpus)) > + continue; > + > if (is_sched_load_balance(cp)) > csa[csn++] = cp; > > - /* skip @cp's subtree */ > - pos_css = css_rightmost_descendant(pos_css); > + /* skip @cp's subtree if not a scheduling domain root */ > + if (!is_sched_domain_root(cp)) > + pos_css = css_rightmost_descendant(pos_css); > } > rcu_read_unlock(); > > @@ -849,7 +860,12 @@ static void rebuild_sched_domains_locked(void) > * passing doms with offlined cpu to partition_sched_domains(). > * Anyways, hotplug work item will rebuild sched domains. > */ > - if (!cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask)) > + if (!top_cpuset.isolation_count && > + !cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask)) > + goto out; > + > + if (top_cpuset.isolation_count && > + !cpumask_subset(top_cpuset.effective_cpus, cpu_active_mask)) > goto out; > > /* Generate domain masks and attrs */ Sorry, that one is bogus. Please ignore that. NAK