Messages in this thread | | | Date | Fri, 28 Sep 2018 18:45:03 -0700 (PDT) | Subject | Re: [PATCH] RISC-V: Show IPI stats | From | Palmer Dabbelt <> |
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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 <anup@brainfault.org> > > 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!
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