The majority of SMP platforms handle their IPIs through do_IRQ()
which calls irq_{enter/exit}(). When a call function IPI is received,
smp_call_function_interrupt() is called which also calls
irq_{enter,exit}(), meaning irq_count is raised twice.
When tick broadcasting is used (which is implemented via a call
function IPI), this incorrectly causes all CPU idle time on the core
receiving broadcast ticks to be accounted as time spent servicing
IRQs, as account_process_tick() will account as such if irq_count is
greater than 1. This results in 100% CPU usage being reported on a
core which receives its ticks via broadcast.
This patch removes the SMP smp_call_function_interrupt() wrapper which
calls irq_{enter,exit}(). Platforms which handle their IPIs through
do_IRQ() now call generic_smp_call_function_interrupt() directly to
avoid incrementing irq_count a second time. Platforms which don't
(loongson, sgi-ip27, sibyte) call generic_smp_call_function_interrupt()
wrapped in irq_{enter,exit}().
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10770/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
14 files changed:
cvmx_write_csr(CVMX_CIU_MBOX_CLRX(coreid), action);
if (action & SMP_CALL_FUNCTION)
cvmx_write_csr(CVMX_CIU_MBOX_CLRX(coreid), action);
if (action & SMP_CALL_FUNCTION)
- smp_call_function_interrupt();
+ generic_smp_call_function_interrupt();
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
extern void play_dead(void);
#endif
extern void play_dead(void);
#endif
-extern asmlinkage void smp_call_function_interrupt(void);
-
static inline void arch_send_call_function_single_ipi(int cpu)
{
extern struct plat_smp_ops *mp_ops; /* private */
static inline void arch_send_call_function_single_ipi(int cpu)
{
extern struct plat_smp_ops *mp_ops; /* private */
if (action == 0)
scheduler_ipi();
else
if (action == 0)
scheduler_ipi();
else
- smp_call_function_interrupt();
+ generic_smp_call_function_interrupt();
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
if (action & SMP_CALL_FUNCTION)
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
if (action & SMP_CALL_FUNCTION)
- smp_call_function_interrupt();
+ generic_smp_call_function_interrupt();
cpu_startup_entry(CPUHP_ONLINE);
}
cpu_startup_entry(CPUHP_ONLINE);
}
-/*
- * Call into both interrupt handlers, as we share the IPI for them
- */
-void __irq_entry smp_call_function_interrupt(void)
-{
- irq_enter();
- generic_smp_call_function_interrupt();
- irq_exit();
-}
-
static void stop_this_cpu(void *dummy)
{
/*
static void stop_this_cpu(void *dummy)
{
/*
static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
{
static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
{
- smp_call_function_interrupt();
+ generic_smp_call_function_interrupt();
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
- if (action & SMP_CALL_FUNCTION)
- smp_call_function_interrupt();
+ if (action & SMP_CALL_FUNCTION) {
+ irq_enter();
+ generic_smp_call_function_interrupt();
+ irq_exit();
+ }
if (action & SMP_ASK_C0COUNT) {
BUG_ON(cpu != 0);
if (action & SMP_ASK_C0COUNT) {
BUG_ON(cpu != 0);
static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
{
static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
{
- smp_call_function_interrupt();
+ generic_smp_call_function_interrupt();
{
clear_c0_eimr(irq);
ack_c0_eirr(irq);
{
clear_c0_eimr(irq);
ack_c0_eirr(irq);
- smp_call_function_interrupt();
+ generic_smp_call_function_interrupt();
static irqreturn_t paravirt_function_interrupt(int irq, void *dev_id)
{
static irqreturn_t paravirt_function_interrupt(int irq, void *dev_id)
{
- smp_call_function_interrupt();
+ generic_smp_call_function_interrupt();
static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
{
static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
{
- smp_call_function_interrupt();
+ generic_smp_call_function_interrupt();
scheduler_ipi();
} else if (pend0 & (1UL << CPU_CALL_A_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ);
scheduler_ipi();
} else if (pend0 & (1UL << CPU_CALL_A_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ);
- smp_call_function_interrupt();
+ irq_enter();
+ generic_smp_call_function_interrupt();
+ irq_exit();
} else if (pend0 & (1UL << CPU_CALL_B_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_CALL_B_IRQ);
} else if (pend0 & (1UL << CPU_CALL_B_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_CALL_B_IRQ);
- smp_call_function_interrupt();
+ irq_enter();
+ generic_smp_call_function_interrupt();
+ irq_exit();
#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/bcm1480_int.h>
#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/bcm1480_int.h>
-extern void smp_call_function_interrupt(void);
-
/*
* These are routines for dealing with the bcm1480 smp capabilities
* independent of board/firmware
/*
* These are routines for dealing with the bcm1480 smp capabilities
* independent of board/firmware
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
- if (action & SMP_CALL_FUNCTION)
- smp_call_function_interrupt();
+ if (action & SMP_CALL_FUNCTION) {
+ irq_enter();
+ generic_smp_call_function_interrupt();
+ irq_exit();
+ }
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
if (action & SMP_RESCHEDULE_YOURSELF)
scheduler_ipi();
- if (action & SMP_CALL_FUNCTION)
- smp_call_function_interrupt();
+ if (action & SMP_CALL_FUNCTION) {
+ irq_enter();
+ generic_smp_call_function_interrupt();
+ irq_exit();
+ }
static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
{
static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
{
- smp_call_function_interrupt();
+ generic_smp_call_function_interrupt();