From 1ac322d0b169c95ce34d55b3ed6d40ce1a5f3a02 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Mon, 25 Jun 2012 13:38:28 -0700 Subject: x86/apic/x2apic: Limit the vector reservation to the user specified mask For the x2apic cluster mode, vector for an interrupt is currently reserved on all the cpu's that are part of the x2apic cluster. But the interrupts will be routed only to the cluster (derived from the first cpu in the mask) members specified in the mask. So there is no need to reserve the vector in the unused cluster members. Modify __assign_irq_vector() to reserve the vectors based on the user specified irq destination mask. If the new mask is a proper subset of the currently used mask, cleanup the vector allocation on the unused cpu members. Also, allow the apic driver to tune the vector domain based on the affinity mask (which in most cases is the user-specified mask). Signed-off-by: Suresh Siddha Acked-by: Yinghai Lu Acked-by: Alexander Gordeev Acked-by: Cyrill Gorcunov Link: http://lkml.kernel.org/r/1340656709-11423-3-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/io_apic.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) (limited to 'arch/x86/kernel/apic/io_apic.c') diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 8a08f09aa505..9684f963befe 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -1113,7 +1113,6 @@ __assign_irq_vector(int irq, struct irq_cfg *cfg, const struct cpumask *mask) */ static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START; static int current_offset = VECTOR_OFFSET_START % 16; - unsigned int old_vector; int cpu, err; cpumask_var_t tmp_mask; @@ -1123,28 +1122,28 @@ __assign_irq_vector(int irq, struct irq_cfg *cfg, const struct cpumask *mask) if (!alloc_cpumask_var(&tmp_mask, GFP_ATOMIC)) return -ENOMEM; - old_vector = cfg->vector; - if (old_vector) { - cpumask_and(tmp_mask, mask, cpu_online_mask); - if (cpumask_subset(tmp_mask, cfg->domain)) { - free_cpumask_var(tmp_mask); - return 0; - } - } - /* Only try and allocate irqs on cpus that are present */ err = -ENOSPC; cpumask_clear(cfg->old_domain); cpu = cpumask_first_and(mask, cpu_online_mask); while (cpu < nr_cpu_ids) { - int new_cpu; - int vector, offset; + int new_cpu, vector, offset; - apic->vector_allocation_domain(cpu, tmp_mask); + apic->vector_allocation_domain(cpu, tmp_mask, mask); if (cpumask_subset(tmp_mask, cfg->domain)) { - free_cpumask_var(tmp_mask); - return 0; + err = 0; + if (cpumask_equal(tmp_mask, cfg->domain)) + break; + /* + * New cpumask using the vector is a proper subset of + * the current in use mask. So cleanup the vector + * allocation for the members that are not used anymore. + */ + cpumask_andnot(cfg->old_domain, cfg->domain, tmp_mask); + cfg->move_in_progress = 1; + cpumask_and(cfg->domain, cfg->domain, tmp_mask); + break; } vector = current_vector; @@ -1172,7 +1171,7 @@ next: /* Found one! */ current_vector = vector; current_offset = offset; - if (old_vector) { + if (cfg->vector) { cfg->move_in_progress = 1; cpumask_copy(cfg->old_domain, cfg->domain); } -- cgit v1.2.3