4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> commit ab25ac02148b600e645f77cfb8b8ea415ed75bb4 upstream. Reusing an existing vector and assigning a new vector has duplicated code. Consolidate it. This is also a preparatory patch for finally plugging the cleanup race. Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Tested-by: Borislav Petkov <bp@xxxxxxxxx> Tested-by: Joe Lawrence <joe.lawrence@xxxxxxxxxxx> Cc: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx> Cc: Jeremiah Mahler <jmmahler@xxxxxxxxx> Cc: andy.shevchenko@xxxxxxxxx Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20151231160106.721599216@xxxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/apic/vector.c | 33 +++++++++++++++------------------ 1 file changed, 15 insertions(+), 18 deletions(-) --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -116,7 +116,7 @@ static int __assign_irq_vector(int irq, */ static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START; static int current_offset = VECTOR_OFFSET_START % 16; - int cpu; + int cpu, vector; if (d->move_in_progress) return -EBUSY; @@ -126,7 +126,7 @@ static int __assign_irq_vector(int irq, cpumask_clear(searched_cpumask); cpu = cpumask_first_and(mask, cpu_online_mask); while (cpu < nr_cpu_ids) { - int new_cpu, vector, offset; + int new_cpu, offset; /* Get the possible target cpus for @mask/@cpu from the apic */ apic->vector_allocation_domain(cpu, vector_cpumask, mask); @@ -146,16 +146,12 @@ static int __assign_irq_vector(int irq, if (cpumask_equal(vector_cpumask, d->domain)) goto success; /* - * 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. + * Mark the cpus which are not longer in the mask for + * cleanup. */ - cpumask_andnot(d->old_domain, d->domain, - vector_cpumask); - d->move_in_progress = - cpumask_intersects(d->old_domain, cpu_online_mask); - cpumask_copy(d->domain, vector_cpumask); - goto success; + cpumask_andnot(d->old_domain, d->domain, vector_cpumask); + vector = d->cfg.vector; + goto update; } vector = current_vector; @@ -181,16 +177,12 @@ next: /* Found one! */ current_vector = vector; current_offset = offset; - if (d->cfg.vector) { + /* Schedule the old vector for cleanup on all cpus */ + if (d->cfg.vector) cpumask_copy(d->old_domain, d->domain); - d->move_in_progress = - cpumask_intersects(d->old_domain, cpu_online_mask); - } for_each_cpu(new_cpu, vector_searchmask) per_cpu(vector_irq, new_cpu)[vector] = irq_to_desc(irq); - d->cfg.vector = vector; - cpumask_copy(d->domain, vector_cpumask); - goto success; + goto update; next_cpu: /* @@ -207,6 +199,11 @@ next_cpu: } return -ENOSPC; +update: + /* Cleanup required ? */ + d->move_in_progress = cpumask_intersects(d->old_domain, cpu_online_mask); + d->cfg.vector = vector; + cpumask_copy(d->domain, vector_cpumask); success: /* * Cache destination APIC IDs into cfg->dest_apicid. This cannot fail -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html