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SubjectRe: [PATCH] IRQ: normalize chip->irq_set_affinity return value on x86 and IA64
Hi Dimitri,
Thanks for review and please refer to the inline comments below.
On 2012-3-8 22:49, Dimitri Sivanich wrote:
> On Tue, Mar 06, 2012 at 11:01:52PM +0800, Jiang Liu wrote:
>> On x86 and IA64 platforms, interrupt controller chip's irq_set_affinity()
>> method always copies affinity mask to irq_data->affinity field but still
>> returns 0(IRQ_SET_MASK_OK). That return value causes the interrupt core
>> logic unnecessarily copies the mask to irq_data->affinity field again.
>> So return IRQ_SET_MASK_OK_NOCOPY instead of IRQ_SET_MASK_OK to get rid of
>> the duplicated copy operation.
>>
>> This patch applies to v3.3-rc6 and has been tested on x86 platforms.
>>
>> Signed-off-by: Jiang Liu<jiang.liu@huawei.com>
>> ---
>> arch/ia64/kernel/iosapic.c | 4 +++-
>> arch/ia64/kernel/msi_ia64.c | 4 ++--
>> arch/ia64/sn/kernel/irq.c | 2 +-
>> arch/ia64/sn/kernel/msi_sn.c | 2 +-
>> arch/x86/kernel/apic/io_apic.c | 11 ++++++-----
>> arch/x86/platform/uv/uv_irq.c | 2 +-
>> kernel/irq/internals.h | 3 +++
>> kernel/irq/manage.c | 39 ++++++++++++++++++++++-----------------
>> kernel/irq/migration.c | 6 +-----
>> 9 files changed, 40 insertions(+), 33 deletions(-)
>>
>> diff --git a/arch/ia64/kernel/iosapic.c b/arch/ia64/kernel/iosapic.c
>> index b0f9afe..98f5fa6 100644
>> --- a/arch/ia64/kernel/iosapic.c
>> +++ b/arch/ia64/kernel/iosapic.c
>> @@ -374,8 +374,10 @@ iosapic_set_affinity(struct irq_data *data, const struct cpumask *mask,
>> iosapic_write(iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
>> }
>>
>
> Maybe I haven't looked thoroughly enough, but could you point out where
> the mask is being copied in this function?
The affinity mask is set through
iosapic_set_affinity()->
set_irq_affinity_info ()
{
if (irq < NR_IRQS) {
cpumask_copy(irq_get_irq_data(irq)->affinity,
cpumask_of(cpu_logical_id(hwid)));
irq_redir[irq] = (char) (redir & 0xff);
}
}

>
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> +#else
>> + return IRQ_SET_MASK_OK;
>> #endif
>> - return 0;
>> }
>>
>> /*
>> diff --git a/arch/ia64/kernel/msi_ia64.c b/arch/ia64/kernel/msi_ia64.c
>> index 94e0db7..e155770 100644
>> --- a/arch/ia64/kernel/msi_ia64.c
>> +++ b/arch/ia64/kernel/msi_ia64.c
>> @@ -41,7 +41,7 @@ static int ia64_set_msi_irq_affinity(struct irq_data *idata,
>> write_msi_msg(irq,&msg);
>> cpumask_copy(idata->affinity, cpumask_of(cpu));
>>
>> - return 0;
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> }
>> #endif /* CONFIG_SMP */
>>
>> @@ -157,7 +157,7 @@ static int dmar_msi_set_affinity(struct irq_data *data,
>> dmar_msi_write(irq,&msg);
>> cpumask_copy(data->affinity, mask);
>>
>> - return 0;
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> }
>> #endif /* CONFIG_SMP */
>>
>> diff --git a/arch/ia64/sn/kernel/irq.c b/arch/ia64/sn/kernel/irq.c
>> index dfac09a..f444208 100644
>> --- a/arch/ia64/sn/kernel/irq.c
>> +++ b/arch/ia64/sn/kernel/irq.c
>> @@ -216,7 +216,7 @@ static int sn_set_affinity_irq(struct irq_data *data,
>> sn_irq_lh[irq], list)
>> (void)sn_retarget_vector(sn_irq_info, nasid, slice);
>
> Again, could you point out where the mask is being copied in this function?
This is through
sn_set_affinity_irq()->sn_retarget_vector()->set_irq_affinity_info()

>
>>
>> - return 0;
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> }
>>
>> #ifdef CONFIG_SMP
>> diff --git a/arch/ia64/sn/kernel/msi_sn.c b/arch/ia64/sn/kernel/msi_sn.c
>> index 2b98b9e..ebb5b55 100644
>> --- a/arch/ia64/sn/kernel/msi_sn.c
>> +++ b/arch/ia64/sn/kernel/msi_sn.c
>> @@ -208,7 +208,7 @@ static int sn_set_msi_irq_affinity(struct irq_data *data,
>> write_msi_msg(irq,&msg);
>> cpumask_copy(data->affinity, cpu_mask);
>>
>> - return 0;
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> }
>> #endif /* CONFIG_SMP */
>>
>> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
>> index fb07275..a81f888 100644
>> --- a/arch/x86/kernel/apic/io_apic.c
>> +++ b/arch/x86/kernel/apic/io_apic.c
>> @@ -2346,6 +2346,7 @@ ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask,
>> /* Only the high 8 bits are valid. */
>> dest = SET_APIC_LOGICAL_ID(dest);
>> __target_IO_APIC_irq(irq, dest, data->chip_data);
>> + ret = IRQ_SET_MASK_OK_NOCOPY;
>> }
>> raw_spin_unlock_irqrestore(&ioapic_lock, flags);
>> return ret;
>> @@ -2404,7 +2405,7 @@ ir_ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask,
>> send_cleanup_vector(cfg);
>>
>> cpumask_copy(data->affinity, mask);
>> - return 0;
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> }
>>
>> #else
>> @@ -3209,7 +3210,7 @@ msi_set_affinity(struct irq_data *data, const struct cpumask *mask, bool force)
>>
>> __write_msi_msg(data->msi_desc,&msg);
>>
>> - return 0;
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> }
>> #endif /* CONFIG_SMP */
>>
>> @@ -3366,7 +3367,7 @@ dmar_msi_set_affinity(struct irq_data *data, const struct cpumask *mask,
>>
>> dmar_msi_write(irq,&msg);
>>
>> - return 0;
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> }
>>
>> #endif /* CONFIG_SMP */
>> @@ -3419,7 +3420,7 @@ static int hpet_msi_set_affinity(struct irq_data *data,
>>
>> hpet_msi_write(data->handler_data,&msg);
>>
>> - return 0;
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> }
>>
>> #endif /* CONFIG_SMP */
>> @@ -3499,7 +3500,7 @@ ht_set_affinity(struct irq_data *data, const struct cpumask *mask, bool force)
>> return -1;
>>
>> target_ht_irq(data->irq, dest, cfg->vector);
>> - return 0;
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> }
>>
>> #endif
>> diff --git a/arch/x86/platform/uv/uv_irq.c b/arch/x86/platform/uv/uv_irq.c
>> index f25c276..a22c416 100644
>> --- a/arch/x86/platform/uv/uv_irq.c
>> +++ b/arch/x86/platform/uv/uv_irq.c
>> @@ -222,7 +222,7 @@ uv_set_irq_affinity(struct irq_data *data, const struct cpumask *mask,
>> if (cfg->move_in_progress)
>> send_cleanup_vector(cfg);
>>
>> - return 0;
>> + return IRQ_SET_MASK_OK_NOCOPY;
>> }
>>
>> /*
>> diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
>> index b795231..2c49c40 100644
>> --- a/kernel/irq/internals.h
>> +++ b/kernel/irq/internals.h
>> @@ -103,6 +103,9 @@ extern int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask);
>>
>> extern void irq_set_thread_affinity(struct irq_desc *desc);
>>
>> +extern int irq_do_set_affinity(struct irq_data *data,
>> + const struct cpumask *dest, bool force);
>> +
>> /* Inline functions for support of irq chips on slow busses */
>> static inline void chip_bus_lock(struct irq_desc *desc)
>> {
>> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
>> index a9a9dbe..b410b0b 100644
>> --- a/kernel/irq/manage.c
>> +++ b/kernel/irq/manage.c
>> @@ -139,6 +139,25 @@ static inline void
>> irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
>> #endif
>>
>> +int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
>> + bool force)
>> +{
>> + struct irq_desc *desc = irq_data_to_desc(data);
>> + struct irq_chip *chip = irq_data_get_irq_chip(data);
>> + int ret;
>> +
>> + ret = chip->irq_set_affinity(data, mask, false);
>> + switch (ret) {
>> + case IRQ_SET_MASK_OK:
>> + cpumask_copy(data->affinity, mask);
>> + case IRQ_SET_MASK_OK_NOCOPY:
>> + irq_set_thread_affinity(desc);
>> + ret = 0;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
>> {
>> struct irq_chip *chip = irq_data_get_irq_chip(data);
>> @@ -149,14 +168,7 @@ int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
>> return -EINVAL;
>>
>> if (irq_can_move_pcntxt(data)) {
>> - ret = chip->irq_set_affinity(data, mask, false);
>> - switch (ret) {
>> - case IRQ_SET_MASK_OK:
>> - cpumask_copy(data->affinity, mask);
>> - case IRQ_SET_MASK_OK_NOCOPY:
>> - irq_set_thread_affinity(desc);
>> - ret = 0;
>> - }
>> + ret = irq_do_set_affinity(data, mask, false);
>> } else {
>> irqd_set_move_pending(data);
>> irq_copy_pending(desc, mask);
>> @@ -280,9 +292,7 @@ EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
>> static int
>> setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
>> {
>> - struct irq_chip *chip = irq_desc_get_chip(desc);
>> struct cpumask *set = irq_default_affinity;
>> - int ret;
>>
>> /* Excludes PER_CPU and NO_BALANCE interrupts */
>> if (!irq_can_set_affinity(irq))
>> @@ -301,13 +311,8 @@ setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
>> }
>>
>> cpumask_and(mask, cpu_online_mask, set);
>> - ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
>> - switch (ret) {
>> - case IRQ_SET_MASK_OK:
>> - cpumask_copy(desc->irq_data.affinity, mask);
>> - case IRQ_SET_MASK_OK_NOCOPY:
>> - irq_set_thread_affinity(desc);
>> - }
>> + irq_do_set_affinity(&desc->irq_data, mask, false);
>> +
>> return 0;
>> }
>> #else
>> diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
>> index 4742090..ef04dab 100644
>> --- a/kernel/irq/migration.c
>> +++ b/kernel/irq/migration.c
>> @@ -44,11 +44,7 @@ void irq_move_masked_irq(struct irq_data *idata)
>> */
>> if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
>> < nr_cpu_ids))
>> - if (!chip->irq_set_affinity(&desc->irq_data,
>> - desc->pending_mask, false)) {
>> - cpumask_copy(desc->irq_data.affinity, desc->pending_mask);
>> - irq_set_thread_affinity(desc);
>> - }
>> + irq_do_set_affinity(&desc->irq_data, desc->pending_mask, false);
>>
>> cpumask_clear(desc->pending_mask);
>> }
>> --
>> 1.7.5.4
>>
>> --
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>
> .
>




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