Messages in this thread | | | Subject | Re: [PATCH v2] RISC-V: Show IPI stats | From | Atish Patra <> | Date | Thu, 13 Sep 2018 10:51:54 -0700 |
| |
On 9/12/18 7:37 AM, 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 <anup@brainfault.org> > --- > > Changes since v1: > - Add stub inline show_ipi_stats() function for !CONFIG_SMP > - Make ipi_names[] dynamically sized at compile time > - Minor beautification of ipi_names[] using tabs > > arch/riscv/include/asm/smp.h | 9 +++++++++ > arch/riscv/kernel/irq.c | 8 ++++++++ > arch/riscv/kernel/smp.c | 30 ++++++++++++++++++++++++++++-- > 3 files changed, 45 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/include/asm/smp.h b/arch/riscv/include/asm/smp.h > index 8145b8657d20..37e909c04f47 100644 > --- a/arch/riscv/include/asm/smp.h > +++ b/arch/riscv/include/asm/smp.h > @@ -36,6 +36,8 @@ static inline bool can_hotplug_cpu(void) > static inline void arch_send_call_wakeup_ipi(int cpu) { } > #endif > > +struct seq_file; > + > #ifdef CONFIG_SMP > > enum ipi_message_type { > @@ -48,6 +50,9 @@ enum ipi_message_type { > void send_ipi_message(const struct cpumask *to_whom, > enum ipi_message_type operation); > > +/* print IPI stats */ > +void show_ipi_stats(struct seq_file *p, int prec); > + > /* SMP initialization hook for setup_arch */ > void __init setup_smp(void); > > @@ -75,6 +80,10 @@ void boot_sec_cpu(void); > > #else > > +static inline void show_ipi_stats(struct seq_file *p, int prec) > +{ > +} > + > static inline int riscv_hartid_to_cpuid(int hartid) > { > return 0; > diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c > index 7e14b0d9a71d..96202139ade5 100644 > --- a/arch/riscv/kernel/irq.c > +++ b/arch/riscv/kernel/irq.c > @@ -8,6 +8,8 @@ > #include <linux/interrupt.h> > #include <linux/irqchip.h> > #include <linux/irqdomain.h> > +#include <linux/seq_file.h> > +#include <asm/smp.h> > > /* > * Possible interrupt causes: > @@ -24,6 +26,12 @@ > */ > #define INTERRUPT_CAUSE_FLAG (1UL << (__riscv_xlen - 1)) > > +int arch_show_interrupts(struct seq_file *p, int prec) > +{ > + show_ipi_stats(p, prec); > + 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..70fd1351d6d9 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_RESCHEDULE] = "Rescheduling interrupts", > + [IPI_CALL_FUNC] = "Function call interrupts", > + [IPI_CALL_WAKEUP] = "CPU wake-up interrupts",
There were some concerns about cpu hotplug patch which introduced IPI_CALL_WAKEUP. I have dropped it as of now from my series. I will send it as a separate patch. So we may want to add IPI_CALL_WAKEUP along with cpu hotplug patch which makes more sense to me.
Other than that, LGTM.
Regards, Atish > +}; > + > +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); >
| |