Re: [PATCH] x86: Distinguish TLB shootdown interrupts from otherfunctions call interrupts
From: Alex Shi
Date: Tue Sep 25 2012 - 22:19:35 EST
On 09/26/2012 10:11 AM, Tomoki Sekiyama wrote:
> Hi Alex,
>
> On 2012/09/25 11:57, Alex Shi wrote:
>> On 09/24/2012 09:37 AM, Alex Shi wrote:
>>
>>> On 09/20/2012 04:50 PM, Tomoki Sekiyama wrote:
>>>
>>>> unsigned int irq_resched_count;
>>>> unsigned int irq_call_count;
>>>> + /* irq_tlb_count is double-counted in irq_call_count, so it must be
>>>> + subtracted from irq_call_count when displaying irq_call_count */
>>>> unsigned int irq_tlb_count;
>>>
>>> Review again this patch, above comments is not kernel compatible format.
>>> Could you change it like standard comment format:
>>>
>>> /*
>>> * xxxxxxx
>>> * xxxx
>>> */
>>>
>>
>> the 3.6 kernel will closed soon. it will be great to has this patch in.
>> So, could you like to refresh your patch with popular comments format? :)
>
> Fixed patch is below.
> Thank you for the review again.
>
Acked-by: Alex Shi <alex.shi@xxxxxxxxx>
> --
> As TLB shootdown requests to other CPU cores are now using function call
> interrupts, TLB shootdowns entry in /proc/interrupts is always shown as 0.
>
> This behavior change was introduced by commit 52aec3308db8 ("x86/tlb:
> replace INVALIDATE_TLB_VECTOR by CALL_FUNCTION_VECTOR").
>
> This patch reverts TLB shootdowns entry in /proc/interrupts to count TLB
> shootdowns separately from the other function call interrupts.
>
> Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@xxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: Alex Shi <alex.shi@xxxxxxxxx>
> ---
> arch/x86/include/asm/hardirq.h | 4 ++++
> arch/x86/kernel/irq.c | 4 ++--
> arch/x86/mm/tlb.c | 2 ++
> 3 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
> index d3895db..81f04ce 100644
> --- a/arch/x86/include/asm/hardirq.h
> +++ b/arch/x86/include/asm/hardirq.h
> @@ -18,6 +18,10 @@ typedef struct {
> #ifdef CONFIG_SMP
> unsigned int irq_resched_count;
> unsigned int irq_call_count;
> + /*
> + * irq_tlb_count is double-counted in irq_call_count, so it must be
> + * subtracted from irq_call_count when displaying irq_call_count
> + */
> unsigned int irq_tlb_count;
> #endif
> #ifdef CONFIG_X86_THERMAL_VECTOR
> diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
> index d44f782..e4595f1 100644
> --- a/arch/x86/kernel/irq.c
> +++ b/arch/x86/kernel/irq.c
> @@ -92,7 +92,8 @@ int arch_show_interrupts(struct seq_file *p, int prec)
> seq_printf(p, " Rescheduling interrupts\n");
> seq_printf(p, "%*s: ", prec, "CAL");
> for_each_online_cpu(j)
> - seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
> + seq_printf(p, "%10u ", irq_stats(j)->irq_call_count -
> + irq_stats(j)->irq_tlb_count);
> seq_printf(p, " Function call interrupts\n");
> seq_printf(p, "%*s: ", prec, "TLB");
> for_each_online_cpu(j)
> @@ -147,7 +148,6 @@ u64 arch_irq_stat_cpu(unsigned int cpu)
> #ifdef CONFIG_SMP
> sum += irq_stats(cpu)->irq_resched_count;
> sum += irq_stats(cpu)->irq_call_count;
> - sum += irq_stats(cpu)->irq_tlb_count;
> #endif
> #ifdef CONFIG_X86_THERMAL_VECTOR
> sum += irq_stats(cpu)->irq_thermal_count;
> diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
> index 613cd83..2d6d8ed 100644
> --- a/arch/x86/mm/tlb.c
> +++ b/arch/x86/mm/tlb.c
> @@ -98,6 +98,8 @@ static void flush_tlb_func(void *info)
> {
> struct flush_tlb_info *f = info;
>
> + inc_irq_stat(irq_tlb_count);
> +
> if (f->flush_mm != this_cpu_read(cpu_tlbstate.active_mm))
> return;
>
>
--
Thanks
Alex
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