From 8b20d2db0a6d2761e0fc156eb74f7a55b92b3147 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 2 Oct 2018 12:15:07 -0700 Subject: [PATCH] RISC-V: Show IPI stats 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 Signed-off-by: Anup Patel [Atish - Fixed checkpatch errors] Signed-off-by: Atish Patra Reviewed-by: Palmer Dabbelt Changes since v2: - Remove use of IPI_CALL_WAKEUP because it's being removed 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 Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/smp.h | 9 +++++++++ arch/riscv/kernel/irq.c | 8 ++++++++ arch/riscv/kernel/smp.c | 39 +++++++++++++++++++++++++++++------- 3 files changed, 49 insertions(+), 7 deletions(-) diff --git a/arch/riscv/include/asm/smp.h b/arch/riscv/include/asm/smp.h index 47fd61dfc897..41aa73b476f4 100644 --- a/arch/riscv/include/asm/smp.h +++ b/arch/riscv/include/asm/smp.h @@ -25,8 +25,13 @@ extern unsigned long __cpuid_to_hartid_map[NR_CPUS]; #define cpuid_to_hartid_map(cpu) __cpuid_to_hartid_map[cpu] +struct seq_file; + #ifdef CONFIG_SMP +/* print IPI stats */ +void show_ipi_stats(struct seq_file *p, int prec); + /* SMP initialization hook for setup_arch */ void __init setup_smp(void); @@ -47,6 +52,10 @@ void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out); #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 ca4593317e45..48e6b7db83a1 100644 --- a/arch/riscv/kernel/irq.c +++ b/arch/riscv/kernel/irq.c @@ -8,6 +8,8 @@ #include #include #include +#include +#include /* * 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) { struct pt_regs *old_regs = set_irq_regs(regs); diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c index 4eac0094f47e..57b1383e5ef7 100644 --- a/arch/riscv/kernel/smp.c +++ b/arch/riscv/kernel/smp.c @@ -22,22 +22,24 @@ #include #include #include +#include #include #include #include -/* A collection of single bit ipi messages. */ -static struct { - unsigned long bits ____cacheline_aligned; -} ipi_data[NR_CPUS] __cacheline_aligned; - enum ipi_message_type { IPI_RESCHEDULE, IPI_CALL_FUNC, IPI_MAX }; +/* 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; + int riscv_hartid_to_cpuid(int hartid) { int i = -1; @@ -67,6 +69,7 @@ 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); @@ -81,11 +84,15 @@ 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); @@ -111,6 +118,24 @@ send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation) sbi_send_ipi(cpumask_bits(&hartid_mask)); } +static const char * const ipi_names[] = { + [IPI_RESCHEDULE] = "Rescheduling interrupts", + [IPI_CALL_FUNC] = "Function call 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); -- GitLab