This patch provides arch_show_interrupts() implementation to
show IPI stats via /proc/interrupts.
Now the contents of /proc/interrupts" will look like below:
CPU0 CPU1 CPU2 CPU3
8: 17 7 6 14 SiFive PLIC 8 virtio0
10: 10 10 9 11 SiFive PLIC 10 ttyS0
IPI0: 170 673 251 79 Rescheduling interrupts
IPI1: 1 12 27 1 Function call interrupts
IPI2: 0 0 0 0 CPU wake-up interrupts
Signed-off-by: Anup Patel <[email protected]>
---
arch/riscv/include/asm/smp.h | 5 +++++
arch/riscv/kernel/irq.c | 9 +++++++++
arch/riscv/kernel/smp.c | 30 ++++++++++++++++++++++++++++--
3 files changed, 42 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/include/asm/smp.h b/arch/riscv/include/asm/smp.h
index 8145b8657d20..a87e292becba 100644
--- a/arch/riscv/include/asm/smp.h
+++ b/arch/riscv/include/asm/smp.h
@@ -48,6 +48,11 @@ enum ipi_message_type {
void send_ipi_message(const struct cpumask *to_whom,
enum ipi_message_type operation);
+struct seq_file;
+
+/* print IPI stats */
+void show_ipi_stats(struct seq_file *p, int prec);
+
/* SMP initialization hook for setup_arch */
void __init setup_smp(void);
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index 7e14b0d9a71d..9177552cd76c 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -8,6 +8,7 @@
#include <linux/interrupt.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
+#include <linux/seq_file.h>
/*
* Possible interrupt causes:
@@ -24,6 +25,14 @@
*/
#define INTERRUPT_CAUSE_FLAG (1UL << (__riscv_xlen - 1))
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+#ifdef CONFIG_SMP
+ show_ipi_stats(p, prec);
+#endif
+ return 0;
+}
+
asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs, unsigned long cause)
{
struct pt_regs *old_regs = set_irq_regs(regs);
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 629456bb6122..4e67a690edbc 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -22,6 +22,7 @@
#include <linux/interrupt.h>
#include <linux/smp.h>
#include <linux/sched.h>
+#include <linux/seq_file.h>
#include <asm/sbi.h>
#include <asm/tlbflush.h>
@@ -29,6 +30,7 @@
/* A collection of single bit ipi messages. */
static struct {
+ unsigned long stats[IPI_MAX] ____cacheline_aligned;
unsigned long bits ____cacheline_aligned;
} ipi_data[NR_CPUS] __cacheline_aligned;
@@ -61,6 +63,7 @@ int setup_profiling_timer(unsigned int multiplier)
void riscv_software_interrupt(void)
{
unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits;
+ unsigned long *stats = ipi_data[smp_processor_id()].stats;
/* Clear pending IPI */
csr_clear(sip, SIE_SSIE);
@@ -75,11 +78,15 @@ void riscv_software_interrupt(void)
if (ops == 0)
return;
- if (ops & (1 << IPI_RESCHEDULE))
+ if (ops & (1 << IPI_RESCHEDULE)) {
+ stats[IPI_RESCHEDULE]++;
scheduler_ipi();
+ }
- if (ops & (1 << IPI_CALL_FUNC))
+ if (ops & (1 << IPI_CALL_FUNC)) {
+ stats[IPI_CALL_FUNC]++;
generic_smp_call_function_interrupt();
+ }
BUG_ON((ops >> IPI_MAX) != 0);
@@ -105,6 +112,25 @@ send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
sbi_send_ipi(cpumask_bits(&hartid_mask));
}
+static const char *ipi_names[IPI_MAX] = {
+ [IPI_RESCHEDULE] = "Rescheduling interrupts",
+ [IPI_CALL_FUNC] = "Function call interrupts",
+ [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
+};
+
+void show_ipi_stats(struct seq_file *p, int prec)
+{
+ unsigned int cpu, i;
+
+ for (i = 0; i < IPI_MAX; i++) {
+ seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
+ prec >= 4 ? " " : "");
+ for_each_online_cpu(cpu)
+ seq_printf(p, "%10lu ", ipi_data[cpu].stats[i]);
+ seq_printf(p, " %s\n", ipi_names[i]);
+ }
+}
+
void arch_send_call_function_ipi_mask(struct cpumask *mask)
{
send_ipi_message(mask, IPI_CALL_FUNC);
--
2.17.1
On Fri, Sep 07, 2018 at 06:14:29PM +0530, Anup Patel wrote:
> This patch provides arch_show_interrupts() implementation to
> show IPI stats via /proc/interrupts.
>
> Now the contents of /proc/interrupts" will look like below:
> CPU0 CPU1 CPU2 CPU3
> 8: 17 7 6 14 SiFive PLIC 8 virtio0
> 10: 10 10 9 11 SiFive PLIC 10 ttyS0
> IPI0: 170 673 251 79 Rescheduling interrupts
> IPI1: 1 12 27 1 Function call interrupts
> IPI2: 0 0 0 0 CPU wake-up interrupts
>
> Signed-off-by: Anup Patel <[email protected]>
Thanks, this looks pretty sensible to me. Maybe we want to also show
timer interrupts if we do this?
> --- a/arch/riscv/kernel/irq.c
> +++ b/arch/riscv/kernel/irq.c
> @@ -8,6 +8,7 @@
> #include <linux/interrupt.h>
> #include <linux/irqchip.h>
> #include <linux/irqdomain.h>
> +#include <linux/seq_file.h>
>
> /*
> * Possible interrupt causes:
> @@ -24,6 +25,14 @@
> */
> #define INTERRUPT_CAUSE_FLAG (1UL << (__riscv_xlen - 1))
>
> +int arch_show_interrupts(struct seq_file *p, int prec)
> +{
> +#ifdef CONFIG_SMP
> + show_ipi_stats(p, prec);
> +#endif
> + return 0;
> +}
If we don't also add timer stats I'd just move arch_show_interrupts
to smp.c and make it conditional. If we don't this split might make
more sense.
> +static const char *ipi_names[IPI_MAX] = {
> + [IPI_RESCHEDULE] = "Rescheduling interrupts",
> + [IPI_CALL_FUNC] = "Function call interrupts",
> + [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
> +};
No need for the explicit array size. Also please use a few tabs to
align this nicely:
static const char *ipi_names[] = {
[IPI_RESCHEDULE] = "Rescheduling interrupts",
[IPI_CALL_FUNC] = "Function call interrupts",
[IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
};
On Mon, Sep 10, 2018 at 7:16 PM, Christoph Hellwig <[email protected]> wrote:
> On Fri, Sep 07, 2018 at 06:14:29PM +0530, Anup Patel wrote:
>> This patch provides arch_show_interrupts() implementation to
>> show IPI stats via /proc/interrupts.
>>
>> Now the contents of /proc/interrupts" will look like below:
>> CPU0 CPU1 CPU2 CPU3
>> 8: 17 7 6 14 SiFive PLIC 8 virtio0
>> 10: 10 10 9 11 SiFive PLIC 10 ttyS0
>> IPI0: 170 673 251 79 Rescheduling interrupts
>> IPI1: 1 12 27 1 Function call interrupts
>> IPI2: 0 0 0 0 CPU wake-up interrupts
>>
>> Signed-off-by: Anup Patel <[email protected]>
>
> Thanks, this looks pretty sensible to me. Maybe we want to also show
> timer interrupts if we do this?
Let's not include timer stats here until RISCV INTC driver is
concluded. We can do it as separate patch if required.
>
>> --- a/arch/riscv/kernel/irq.c
>> +++ b/arch/riscv/kernel/irq.c
>> @@ -8,6 +8,7 @@
>> #include <linux/interrupt.h>
>> #include <linux/irqchip.h>
>> #include <linux/irqdomain.h>
>> +#include <linux/seq_file.h>
>>
>> /*
>> * Possible interrupt causes:
>> @@ -24,6 +25,14 @@
>> */
>> #define INTERRUPT_CAUSE_FLAG (1UL << (__riscv_xlen - 1))
>>
>> +int arch_show_interrupts(struct seq_file *p, int prec)
>> +{
>> +#ifdef CONFIG_SMP
>> + show_ipi_stats(p, prec);
>> +#endif
>> + return 0;
>> +}
>
> If we don't also add timer stats I'd just move arch_show_interrupts
> to smp.c and make it conditional. If we don't this split might make
> more sense.
I understand you want to avoid #ifdef here. We can do same thing
by having empty inline function show_ipi_stats() in asm/smp.h for
!CONFIG_SMP case. This way we can keep arch_show_interrupts()
in kernel/irq.c which is intuitively correct location for
arch_show_interrupts().
>
>> +static const char *ipi_names[IPI_MAX] = {
>> + [IPI_RESCHEDULE] = "Rescheduling interrupts",
>> + [IPI_CALL_FUNC] = "Function call interrupts",
>> + [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
>> +};
>
> No need for the explicit array size. Also please use a few tabs to
> align this nicely:
>
> static const char *ipi_names[] = {
> [IPI_RESCHEDULE] = "Rescheduling interrupts",
> [IPI_CALL_FUNC] = "Function call interrupts",
> [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
> };
Sure, will do.
Regards,
Anup
On Mon, 10 Sep 2018 06:46:59 PDT (-0700), Christoph Hellwig wrote:
> On Fri, Sep 07, 2018 at 06:14:29PM +0530, Anup Patel wrote:
>> This patch provides arch_show_interrupts() implementation to
>> show IPI stats via /proc/interrupts.
>>
>> Now the contents of /proc/interrupts" will look like below:
>> CPU0 CPU1 CPU2 CPU3
>> 8: 17 7 6 14 SiFive PLIC 8 virtio0
>> 10: 10 10 9 11 SiFive PLIC 10 ttyS0
>> IPI0: 170 673 251 79 Rescheduling interrupts
>> IPI1: 1 12 27 1 Function call interrupts
>> IPI2: 0 0 0 0 CPU wake-up interrupts
>>
>> Signed-off-by: Anup Patel <[email protected]>
>
> Thanks, this looks pretty sensible to me. Maybe we want to also show
> timer interrupts if we do this?
IIRC we used to have some issue where the timer interrupt ID in
/proc/interrupts aliased with a possible PLIC interrupt ID, but that was back
when we had a big mess of chained interrupt drivers that didn't really talk to
each other. I think at some point I might have just removed the timer
interrupt from /proc/interrupts as a hack, but now that our interrupt
controller mess is sorted out it'd be better to have it.
I'm fine taking this without the timer interrupts, as something is better than
nothing.
>> --- a/arch/riscv/kernel/irq.c
>> +++ b/arch/riscv/kernel/irq.c
>> @@ -8,6 +8,7 @@
>> #include <linux/interrupt.h>
>> #include <linux/irqchip.h>
>> #include <linux/irqdomain.h>
>> +#include <linux/seq_file.h>
>>
>> /*
>> * Possible interrupt causes:
>> @@ -24,6 +25,14 @@
>> */
>> #define INTERRUPT_CAUSE_FLAG (1UL << (__riscv_xlen - 1))
>>
>> +int arch_show_interrupts(struct seq_file *p, int prec)
>> +{
>> +#ifdef CONFIG_SMP
>> + show_ipi_stats(p, prec);
>> +#endif
>> + return 0;
>> +}
>
> If we don't also add timer stats I'd just move arch_show_interrupts
> to smp.c and make it conditional. If we don't this split might make
> more sense.
Makes sense, but I think timer interrupts are more interesting to see than IPIs
so we'll eventually pipe them through. Might just be my workloads, though :)
>> +static const char *ipi_names[IPI_MAX] = {
>> + [IPI_RESCHEDULE] = "Rescheduling interrupts",
>> + [IPI_CALL_FUNC] = "Function call interrupts",
>> + [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
>> +};
>
> No need for the explicit array size. Also please use a few tabs to
> align this nicely:
>
> static const char *ipi_names[] = {
> [IPI_RESCHEDULE] = "Rescheduling interrupts",
> [IPI_CALL_FUNC] = "Function call interrupts",
> [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
> };
I don't see a v2 of this, was there one? If not then I'll just clean up
ipi_names and drop this on for-next.
Thanks for the patch!
On Sat, Sep 29, 2018 at 7:15 AM Palmer Dabbelt <[email protected]> wrote:
>
> On Mon, 10 Sep 2018 06:46:59 PDT (-0700), Christoph Hellwig wrote:
> > On Fri, Sep 07, 2018 at 06:14:29PM +0530, Anup Patel wrote:
> >> This patch provides arch_show_interrupts() implementation to
> >> show IPI stats via /proc/interrupts.
> >>
> >> Now the contents of /proc/interrupts" will look like below:
> >> CPU0 CPU1 CPU2 CPU3
> >> 8: 17 7 6 14 SiFive PLIC 8 virtio0
> >> 10: 10 10 9 11 SiFive PLIC 10 ttyS0
> >> IPI0: 170 673 251 79 Rescheduling interrupts
> >> IPI1: 1 12 27 1 Function call interrupts
> >> IPI2: 0 0 0 0 CPU wake-up interrupts
> >>
> >> Signed-off-by: Anup Patel <[email protected]>
> >
> > Thanks, this looks pretty sensible to me. Maybe we want to also show
> > timer interrupts if we do this?
>
> IIRC we used to have some issue where the timer interrupt ID in
> /proc/interrupts aliased with a possible PLIC interrupt ID, but that was back
> when we had a big mess of chained interrupt drivers that didn't really talk to
> each other. I think at some point I might have just removed the timer
> interrupt from /proc/interrupts as a hack, but now that our interrupt
> controller mess is sorted out it'd be better to have it.
If we have irqdomain and irqchip for HLIC then showing timer interrupts
becomes cleaner. My RISCV INTC patch achieves this.
>
> I'm fine taking this without the timer interrupts, as something is better than
> nothing.
Sure.
>
> >> --- a/arch/riscv/kernel/irq.c
> >> +++ b/arch/riscv/kernel/irq.c
> >> @@ -8,6 +8,7 @@
> >> #include <linux/interrupt.h>
> >> #include <linux/irqchip.h>
> >> #include <linux/irqdomain.h>
> >> +#include <linux/seq_file.h>
> >>
> >> /*
> >> * Possible interrupt causes:
> >> @@ -24,6 +25,14 @@
> >> */
> >> #define INTERRUPT_CAUSE_FLAG (1UL << (__riscv_xlen - 1))
> >>
> >> +int arch_show_interrupts(struct seq_file *p, int prec)
> >> +{
> >> +#ifdef CONFIG_SMP
> >> + show_ipi_stats(p, prec);
> >> +#endif
> >> + return 0;
> >> +}
> >
> > If we don't also add timer stats I'd just move arch_show_interrupts
> > to smp.c and make it conditional. If we don't this split might make
> > more sense.
>
> Makes sense, but I think timer interrupts are more interesting to see than IPIs
> so we'll eventually pipe them through. Might just be my workloads, though :)
>
> >> +static const char *ipi_names[IPI_MAX] = {
> >> + [IPI_RESCHEDULE] = "Rescheduling interrupts",
> >> + [IPI_CALL_FUNC] = "Function call interrupts",
> >> + [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
> >> +};
> >
> > No need for the explicit array size. Also please use a few tabs to
> > align this nicely:
> >
> > static const char *ipi_names[] = {
> > [IPI_RESCHEDULE] = "Rescheduling interrupts",
> > [IPI_CALL_FUNC] = "Function call interrupts",
> > [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
> > };
>
> I don't see a v2 of this, was there one? If not then I'll just clean up
> ipi_names and drop this on for-next.
>
> Thanks for the patch!
I will send v3 patch because IPI_CALL_WAKEUP is not going to be available.
I will base v3 patch upon v5 of Atish's patchset. Atish will take v3 of this
patch and make it part of his v6 patchset so that it will be easy for you
to apply.
Regards,
Anup
On Fri, 28 Sep 2018 23:09:56 PDT (-0700), [email protected] wrote:
> On Sat, Sep 29, 2018 at 7:15 AM Palmer Dabbelt <[email protected]> wrote:
>>
>> On Mon, 10 Sep 2018 06:46:59 PDT (-0700), Christoph Hellwig wrote:
>> > On Fri, Sep 07, 2018 at 06:14:29PM +0530, Anup Patel wrote:
>> >> This patch provides arch_show_interrupts() implementation to
>> >> show IPI stats via /proc/interrupts.
>> >>
>> >> Now the contents of /proc/interrupts" will look like below:
>> >> CPU0 CPU1 CPU2 CPU3
>> >> 8: 17 7 6 14 SiFive PLIC 8 virtio0
>> >> 10: 10 10 9 11 SiFive PLIC 10 ttyS0
>> >> IPI0: 170 673 251 79 Rescheduling interrupts
>> >> IPI1: 1 12 27 1 Function call interrupts
>> >> IPI2: 0 0 0 0 CPU wake-up interrupts
>> >>
>> >> Signed-off-by: Anup Patel <[email protected]>
>> >
>> > Thanks, this looks pretty sensible to me. Maybe we want to also show
>> > timer interrupts if we do this?
>>
>> IIRC we used to have some issue where the timer interrupt ID in
>> /proc/interrupts aliased with a possible PLIC interrupt ID, but that was back
>> when we had a big mess of chained interrupt drivers that didn't really talk to
>> each other. I think at some point I might have just removed the timer
>> interrupt from /proc/interrupts as a hack, but now that our interrupt
>> controller mess is sorted out it'd be better to have it.
>
> If we have irqdomain and irqchip for HLIC then showing timer interrupts
> becomes cleaner. My RISCV INTC patch achieves this.
>
>>
>> I'm fine taking this without the timer interrupts, as something is better than
>> nothing.
>
> Sure.
>
>>
>> >> --- a/arch/riscv/kernel/irq.c
>> >> +++ b/arch/riscv/kernel/irq.c
>> >> @@ -8,6 +8,7 @@
>> >> #include <linux/interrupt.h>
>> >> #include <linux/irqchip.h>
>> >> #include <linux/irqdomain.h>
>> >> +#include <linux/seq_file.h>
>> >>
>> >> /*
>> >> * Possible interrupt causes:
>> >> @@ -24,6 +25,14 @@
>> >> */
>> >> #define INTERRUPT_CAUSE_FLAG (1UL << (__riscv_xlen - 1))
>> >>
>> >> +int arch_show_interrupts(struct seq_file *p, int prec)
>> >> +{
>> >> +#ifdef CONFIG_SMP
>> >> + show_ipi_stats(p, prec);
>> >> +#endif
>> >> + return 0;
>> >> +}
>> >
>> > If we don't also add timer stats I'd just move arch_show_interrupts
>> > to smp.c and make it conditional. If we don't this split might make
>> > more sense.
>>
>> Makes sense, but I think timer interrupts are more interesting to see than IPIs
>> so we'll eventually pipe them through. Might just be my workloads, though :)
>>
>> >> +static const char *ipi_names[IPI_MAX] = {
>> >> + [IPI_RESCHEDULE] = "Rescheduling interrupts",
>> >> + [IPI_CALL_FUNC] = "Function call interrupts",
>> >> + [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
>> >> +};
>> >
>> > No need for the explicit array size. Also please use a few tabs to
>> > align this nicely:
>> >
>> > static const char *ipi_names[] = {
>> > [IPI_RESCHEDULE] = "Rescheduling interrupts",
>> > [IPI_CALL_FUNC] = "Function call interrupts",
>> > [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
>> > };
>>
>> I don't see a v2 of this, was there one? If not then I'll just clean up
>> ipi_names and drop this on for-next.
>>
>> Thanks for the patch!
>
> I will send v3 patch because IPI_CALL_WAKEUP is not going to be available.
>
> I will base v3 patch upon v5 of Atish's patchset. Atish will take v3 of this
> patch and make it part of his v6 patchset so that it will be easy for you
> to apply.
Thanks!