From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757411Ab2ESUxk (ORCPT ); Sat, 19 May 2012 16:53:40 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:47573 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756173Ab2ESUxh convert rfc822-to-8bit (ORCPT ); Sat, 19 May 2012 16:53:37 -0400 MIME-Version: 1.0 In-Reply-To: <20120518102640.GB31517@dhcp-26-207.brq.redhat.com> References: <20120518102640.GB31517@dhcp-26-207.brq.redhat.com> Date: Sat, 19 May 2012 13:53:36 -0700 X-Google-Sender-Auth: nkKxDZiTT36e99z4HFzojA8CML8 Message-ID: Subject: Re: [PATCH 2/3] x86: x2apic/cluster: Make use of lowest priority delivery mode From: Yinghai Lu To: Alexander Gordeev Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Suresh Siddha , Cyrill Gorcunov Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 18, 2012 at 3:26 AM, Alexander Gordeev wrote: > Currently x2APIC in logical destination mode delivers interrupts to a > single CPU, no matter how many CPUs were specified in the destination > cpumask. > > This fix enables delivery of interrupts to multiple CPUs by bit-ORing > Logical IDs of destination CPUs that have matching Cluster ID. > > Because only one cluster could be specified in a message destination > address, the destination cpumask is tried for a cluster that contains > maximum number of CPUs matching this cpumask. The CPUs in this cluster > are selected to receive the interrupts while all other CPUs (in the > cpumask) are ignored. > > Signed-off-by: Alexander Gordeev > --- >  arch/x86/include/asm/x2apic.h         |    9 -- >  arch/x86/kernel/apic/x2apic_cluster.c |  140 +++++++++++++++++++++++++++++---- >  arch/x86/kernel/apic/x2apic_phys.c    |    9 ++- >  3 files changed, 131 insertions(+), 27 deletions(-) > > diff --git a/arch/x86/include/asm/x2apic.h b/arch/x86/include/asm/x2apic.h > index 92e54ab..7a5a832 100644 > --- a/arch/x86/include/asm/x2apic.h > +++ b/arch/x86/include/asm/x2apic.h > @@ -28,15 +28,6 @@ static int x2apic_apic_id_registered(void) >        return 1; >  } > > -/* > - * For now each logical cpu is in its own vector allocation domain. > - */ > -static void x2apic_vector_allocation_domain(int cpu, struct cpumask *retmask) > -{ > -       cpumask_clear(retmask); > -       cpumask_set_cpu(cpu, retmask); > -} > - >  static void >  __x2apic_send_IPI_dest(unsigned int apicid, int vector, unsigned int dest) >  { > diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c > index 8f012b2..f8fa4c4 100644 > --- a/arch/x86/kernel/apic/x2apic_cluster.c > +++ b/arch/x86/kernel/apic/x2apic_cluster.c > @@ -96,36 +96,142 @@ static void x2apic_send_IPI_all(int vector) >        __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLINC); >  } > > +static inline unsigned int > +__x2apic_cluster_to_apicid(int cpu_in_cluster, const struct cpumask *cpumask) > +{ > +       unsigned int apicid = 0; > +       int cpu; > + > +       for_each_cpu_and(cpu, per_cpu(cpus_in_cluster, cpu_in_cluster), cpumask) > +               apicid |= per_cpu(x86_cpu_to_logical_apicid, cpu); > + > +       return apicid; > +} > + > +static int > +__x2apic_cpu_mask_to_apicid(const struct cpumask *cpumask, unsigned int *apicid) > +{ > +       int ret = 0; > +       int cpu, heaviest; > +       unsigned int weight, max_weight; > +       cpumask_var_t target_cpus, cluster_cpus; > + > +       if (unlikely(!alloc_cpumask_var(&target_cpus, GFP_ATOMIC))) { > +               ret = -ENOMEM; > +               goto out; > +       } > +       if (unlikely(!alloc_cpumask_var(&cluster_cpus, GFP_ATOMIC))) { > +               ret = -ENOMEM; > +               goto out_free_target_cpus; > +       } > + > +       cpumask_and(target_cpus, cpumask, cpu_online_mask); > +       max_weight = 0; > + > +       for_each_cpu(cpu, target_cpus) { > +               cpumask_and(cluster_cpus, per_cpu(cpus_in_cluster, cpu), cpumask); > + > +               weight = cpumask_weight(cluster_cpus); > +               if (weight > max_weight) { > +                       max_weight = weight; > +                       heaviest = cpu; > +               } > + > +               cpumask_andnot(target_cpus, target_cpus, cluster_cpus); > +       } > + > +       if (!max_weight) { > +               ret = -EINVAL; > +               goto out_free_cluster_cpus; > +       } > + > +       *apicid = __x2apic_cluster_to_apicid(heaviest, cpumask); > + > +out_free_cluster_cpus: > +       free_cpumask_var(cluster_cpus); > +out_free_target_cpus: > +       free_cpumask_var(target_cpus); > +out: > +       return ret; > +} > + >  static unsigned int x2apic_cpu_mask_to_apicid(const struct cpumask *cpumask) >  { > -       /* > -        * We're using fixed IRQ delivery, can only return one logical APIC ID. > -        * May as well be the first. > -        */ > -       int cpu = cpumask_first(cpumask); > +       int err; > +       int cpu; > +       unsigned int apicid; > > -       if ((unsigned)cpu < nr_cpu_ids) > -               return per_cpu(x86_cpu_to_logical_apicid, cpu); > -       else > -               return BAD_APICID; > +       err = __x2apic_cpu_mask_to_apicid(cpumask, &apicid); > +       WARN_ON(err); > + > +       if (!err) > +               return apicid; > + > +       if (err == -ENOMEM) { > +               for_each_cpu(cpu, cpumask) { > +                       if (cpumask_test_cpu(cpu, cpu_online_mask)) > +                               break; > +               } > +               if (cpu < nr_cpu_ids) > +                       return __x2apic_cluster_to_apicid(cpu, cpumask); > +       } > + > +       return BAD_APICID; >  } > >  static unsigned int >  x2apic_cpu_mask_to_apicid_and(const struct cpumask *cpumask, >                              const struct cpumask *andmask) >  { > -       int cpu; > +       int err; > +       int cpu, first_cpu; > +       unsigned int apicid; > +       cpumask_var_t target_cpus; > + > +       if (likely(alloc_cpumask_var(&target_cpus, GFP_ATOMIC))) { > +               cpumask_and(target_cpus, cpumask, andmask); > + > +               err = __x2apic_cpu_mask_to_apicid(target_cpus, &apicid); > + > +               free_cpumask_var(target_cpus); > + > +               if (!err) > +                       return apicid; > +       } else { > +               err = -ENOMEM; > +       } > + > +       WARN_ON(err); > + > +       if (err != -ENOMEM) > +               return 0; > + > +       apicid = 0; > +       first_cpu = nr_cpu_ids; > > -       /* > -        * We're using fixed IRQ delivery, can only return one logical APIC ID. > -        * May as well be the first. > -        */ >        for_each_cpu_and(cpu, cpumask, andmask) { > -               if (cpumask_test_cpu(cpu, cpu_online_mask)) > +               if (cpumask_test_cpu(cpu, cpu_online_mask)) { > +                       first_cpu = cpu; >                        break; > +               } > +       } > + > +       if (first_cpu < nr_cpu_ids) { > +               for_each_cpu_and(cpu, per_cpu(cpus_in_cluster, first_cpu), > +                                cpumask) { > +                       if (!cpumask_test_cpu(cpu, andmask)) > +                               continue; > +                       apicid |= per_cpu(x86_cpu_to_logical_apicid, cpu); > +               } >        } > > -       return per_cpu(x86_cpu_to_logical_apicid, cpu); > +       return apicid; > +} > + > +static void > +x2apic_cluster_vector_allocation_domain(int cpu, struct cpumask *retmask) > +{ > +       cpumask_copy(retmask, cpu_possible_mask); why not using per_cpu(cpus_in_cluster, cpu) instead? also you may add one per cpu var like x86_cpu_to_logical_cluster_apicid. Yinghai