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 <a...@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!
