[tip: smp/core] treewide: Trace IPIs sent via smp_send_reschedule()

From: tip-bot2 for Valentin Schneider
Date: Tue Mar 28 2023 - 04:35:03 EST

The following commit has been merged into the smp/core branch of tip:

Commit-ID: 4c8c3c7f70a6779d30f5492acbc9978f4636fe7a
Gitweb: https://git.kernel.org/tip/4c8c3c7f70a6779d30f5492acbc9978f4636fe7a
Author: Valentin Schneider <vschneid@xxxxxxxxxx>
AuthorDate: Tue, 07 Mar 2023 14:35:56
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 24 Mar 2023 11:01:28 +01:00

treewide: Trace IPIs sent via smp_send_reschedule()

To be able to trace invocations of smp_send_reschedule(), rename the
arch-specific definitions of it to arch_smp_send_reschedule() and wrap it
into an smp_send_reschedule() that contains a tracepoint.

Changes to include the declaration of the tracepoint were driven by the
following coccinelle script:

@func_use@
@@
smp_send_reschedule(...);

@include@
@@
#include <trace/events/ipi.h>

@no_include depends on func_use && !include@
@@
#include <...>
+
+ #include <trace/events/ipi.h>

[csky bits]
[riscv bits]
Signed-off-by: Valentin Schneider <vschneid@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Guo Ren <guoren@xxxxxxxxxx>
Acked-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230307143558.294354-6-vschneid@xxxxxxxxxx
---
arch/alpha/kernel/smp.c | 2 +-
arch/arc/kernel/smp.c | 2 +-
arch/arm/kernel/smp.c | 2 +-
arch/arm/mach-actions/platsmp.c | 2 ++
arch/arm64/kernel/smp.c | 2 +-
arch/csky/kernel/smp.c | 2 +-
arch/hexagon/kernel/smp.c | 2 +-
arch/ia64/kernel/smp.c | 4 ++--
arch/loongarch/kernel/smp.c | 4 ++--
arch/mips/include/asm/smp.h | 2 +-
arch/mips/kernel/rtlx-cmp.c | 2 ++
arch/openrisc/kernel/smp.c | 2 +-
arch/parisc/kernel/smp.c | 4 ++--
arch/powerpc/kernel/smp.c | 6 ++++--
arch/powerpc/kvm/book3s_hv.c | 3 +++
arch/powerpc/platforms/powernv/subcore.c | 2 ++
arch/riscv/kernel/smp.c | 4 ++--
arch/s390/kernel/smp.c | 2 +-
arch/sh/kernel/smp.c | 2 +-
arch/sparc/kernel/smp_32.c | 2 +-
arch/sparc/kernel/smp_64.c | 2 +-
arch/x86/include/asm/smp.h | 2 +-
arch/x86/kvm/svm/svm.c | 4 ++++
arch/x86/kvm/x86.c | 2 ++
arch/xtensa/kernel/smp.c | 2 +-
include/linux/smp.h | 11 +++++++++--
virt/kvm/kvm_main.c | 3 +++
27 files changed, 53 insertions(+), 26 deletions(-)

diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
index 0ede4b0..7439b23 100644
--- a/arch/alpha/kernel/smp.c
+++ b/arch/alpha/kernel/smp.c
@@ -562,7 +562,7 @@ handle_ipi(struct pt_regs *regs)
}

void
-smp_send_reschedule(int cpu)
+arch_smp_send_reschedule(int cpu)
{
#ifdef DEBUG_IPI_MSG
if (cpu == hard_smp_processor_id())
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index ad93fe6..409cfa4 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -292,7 +292,7 @@ static void ipi_send_msg(const struct cpumask *callmap, enum ipi_msg_type msg)
ipi_send_msg_one(cpu, msg);
}

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
ipi_send_msg_one(cpu, IPI_RESCHEDULE);
}
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 5edf092..b350bfc 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -746,7 +746,7 @@ void __init set_smp_ipi_range(int ipi_base, int n)
ipi_setup(smp_processor_id());
}

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
}
diff --git a/arch/arm/mach-actions/platsmp.c b/arch/arm/mach-actions/platsmp.c
index f26618b..7b208e9 100644
--- a/arch/arm/mach-actions/platsmp.c
+++ b/arch/arm/mach-actions/platsmp.c
@@ -20,6 +20,8 @@
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>

+#include <trace/events/ipi.h>
+
#define OWL_CPU1_ADDR 0x50
#define OWL_CPU1_FLAG 0x5c

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 438c16f..66f2745 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -976,7 +976,7 @@ void __init set_smp_ipi_range(int ipi_base, int n)
ipi_setup(smp_processor_id());
}

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
}
diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c
index b45d107..be77383 100644
--- a/arch/csky/kernel/smp.c
+++ b/arch/csky/kernel/smp.c
@@ -140,7 +140,7 @@ void smp_send_stop(void)
on_each_cpu(ipi_stop, NULL, 1);
}

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
}
diff --git a/arch/hexagon/kernel/smp.c b/arch/hexagon/kernel/smp.c
index 4ba93e5..4e8bee2 100644
--- a/arch/hexagon/kernel/smp.c
+++ b/arch/hexagon/kernel/smp.c
@@ -217,7 +217,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
}
}

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
send_ipi(cpumask_of(cpu), IPI_RESCHEDULE);
}
diff --git a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c
index e2cc59d..ea4f009 100644
--- a/arch/ia64/kernel/smp.c
+++ b/arch/ia64/kernel/smp.c
@@ -220,11 +220,11 @@ kdump_smp_send_init(void)
* Called with preemption disabled.
*/
void
-smp_send_reschedule (int cpu)
+arch_smp_send_reschedule (int cpu)
{
ia64_send_ipi(cpu, IA64_IPI_RESCHEDULE, IA64_IPI_DM_INT, 0);
}
-EXPORT_SYMBOL_GPL(smp_send_reschedule);
+EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);

/*
* Called with preemption disabled.
diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
index 8c6e227..8322561 100644
--- a/arch/loongarch/kernel/smp.c
+++ b/arch/loongarch/kernel/smp.c
@@ -155,11 +155,11 @@ void loongson_send_ipi_mask(const struct cpumask *mask, unsigned int action)
* it goes straight through and wastes no time serializing
* anything. Worst case is that we lose a reschedule ...
*/
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
loongson_send_ipi_single(cpu, SMP_RESCHEDULE);
}
-EXPORT_SYMBOL_GPL(smp_send_reschedule);
+EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);

irqreturn_t loongson_ipi_interrupt(int irq, void *dev)
{
diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h
index 5d9ff61..9806e79 100644
--- a/arch/mips/include/asm/smp.h
+++ b/arch/mips/include/asm/smp.h
@@ -66,7 +66,7 @@ extern void calculate_cpu_foreign_map(void);
* it goes straight through and wastes no time serializing
* anything. Worst case is that we lose a reschedule ...
*/
-static inline void smp_send_reschedule(int cpu)
+static inline void arch_smp_send_reschedule(int cpu)
{
extern const struct plat_smp_ops *mp_ops; /* private */

diff --git a/arch/mips/kernel/rtlx-cmp.c b/arch/mips/kernel/rtlx-cmp.c
index d26dcc4..e991cc9 100644
--- a/arch/mips/kernel/rtlx-cmp.c
+++ b/arch/mips/kernel/rtlx-cmp.c
@@ -17,6 +17,8 @@
#include <asm/vpe.h>
#include <asm/rtlx.h>

+#include <trace/events/ipi.h>
+
static int major;

static void rtlx_interrupt(void)
diff --git a/arch/openrisc/kernel/smp.c b/arch/openrisc/kernel/smp.c
index e141909..0a7a059 100644
--- a/arch/openrisc/kernel/smp.c
+++ b/arch/openrisc/kernel/smp.c
@@ -173,7 +173,7 @@ void handle_IPI(unsigned int ipi_msg)
}
}

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
}
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 7dbd92c..b7fc859 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -246,8 +246,8 @@ void kgdb_roundup_cpus(void)
inline void
smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }

-void
-smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
+void
+arch_smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }

void
smp_send_all_nop(void)
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 6b90f10..35f101c 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -61,6 +61,8 @@
#include <asm/kup.h>
#include <asm/fadump.h>

+#include <trace/events/ipi.h>
+
#ifdef DEBUG
#include <asm/udbg.h>
#define DBG(fmt...) udbg_printf(fmt)
@@ -364,12 +366,12 @@ static inline void do_message_pass(int cpu, int msg)
#endif
}

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
if (likely(smp_ops))
do_message_pass(cpu, PPC_MSG_RESCHEDULE);
}
-EXPORT_SYMBOL_GPL(smp_send_reschedule);
+EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);

void arch_send_call_function_single_ipi(int cpu)
{
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 6ba68dd..3b70b5f 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -43,6 +43,7 @@
#include <linux/compiler.h>
#include <linux/of.h>
#include <linux/irqdomain.h>
+#include <linux/smp.h>

#include <asm/ftrace.h>
#include <asm/reg.h>
@@ -80,6 +81,8 @@
#include <asm/dtl.h>
#include <asm/plpar_wrappers.h>

+#include <trace/events/ipi.h>
+
#include "book3s.h"
#include "book3s_hv.h"

diff --git a/arch/powerpc/platforms/powernv/subcore.c b/arch/powerpc/platforms/powernv/subcore.c
index 7e98b00..c53c4c7 100644
--- a/arch/powerpc/platforms/powernv/subcore.c
+++ b/arch/powerpc/platforms/powernv/subcore.c
@@ -20,6 +20,8 @@
#include <asm/opal.h>
#include <asm/smp.h>

+#include <trace/events/ipi.h>
+
#include "subcore.h"
#include "powernv.h"

diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 8c3b59f..42e9656 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -328,8 +328,8 @@ bool smp_crash_stop_failed(void)
}
#endif

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
send_ipi_single(cpu, IPI_RESCHEDULE);
}
-EXPORT_SYMBOL_GPL(smp_send_reschedule);
+EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index d488845..a710319 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -553,7 +553,7 @@ void arch_send_call_function_single_ipi(int cpu)
* it goes straight through and wastes no time serializing
* anything. Worst case is that we lose a reschedule ...
*/
-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
}
diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c
index 65924d9..5cf35a7 100644
--- a/arch/sh/kernel/smp.c
+++ b/arch/sh/kernel/smp.c
@@ -256,7 +256,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
(bogosum / (5000/HZ)) % 100);
}

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
}
diff --git a/arch/sparc/kernel/smp_32.c b/arch/sparc/kernel/smp_32.c
index ad8094d..87eaa77 100644
--- a/arch/sparc/kernel/smp_32.c
+++ b/arch/sparc/kernel/smp_32.c
@@ -120,7 +120,7 @@ void cpu_panic(void)

struct linux_prom_registers smp_penguin_ctable = { 0 };

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
/*
* CPU model dependent way of implementing IPI generation targeting
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index a55295d..e5964d1 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -1430,7 +1430,7 @@ static unsigned long send_cpu_poke(int cpu)
return hv_err;
}

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
if (cpu == smp_processor_id()) {
WARN_ON_ONCE(preemptible());
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index b4dbb20..f975712 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -98,7 +98,7 @@ static inline void play_dead(void)
smp_ops.play_dead();
}

-static inline void smp_send_reschedule(int cpu)
+static inline void arch_smp_send_reschedule(int cpu)
{
smp_ops.smp_send_reschedule(cpu);
}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 252e7f3..424fcdb 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -27,6 +27,7 @@
#include <linux/swap.h>
#include <linux/rwsem.h>
#include <linux/cc_platform.h>
+#include <linux/smp.h>

#include <asm/apic.h>
#include <asm/perf_event.h>
@@ -41,6 +42,9 @@
#include <asm/fpu/api.h>

#include <asm/virtext.h>
+
+#include <trace/events/ipi.h>
+
#include "trace.h"

#include "svm.h"
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7713420..07ba937 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -60,7 +60,9 @@
#include <linux/mem_encrypt.h>
#include <linux/entry-kvm.h>
#include <linux/suspend.h>
+#include <linux/smp.h>

+#include <trace/events/ipi.h>
#include <trace/events/kvm.h>

#include <asm/debugreg.h>
diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c
index 4dc109d..d95907b 100644
--- a/arch/xtensa/kernel/smp.c
+++ b/arch/xtensa/kernel/smp.c
@@ -389,7 +389,7 @@ void arch_send_call_function_single_ipi(int cpu)
send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
}

-void smp_send_reschedule(int cpu)
+void arch_smp_send_reschedule(int cpu)
{
send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
}
diff --git a/include/linux/smp.h b/include/linux/smp.h
index a80ab58..c036a22 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -125,8 +125,15 @@ extern void smp_send_stop(void);
/*
* sends a 'reschedule' event to another CPU:
*/
-extern void smp_send_reschedule(int cpu);
-
+extern void arch_smp_send_reschedule(int cpu);
+/*
+ * scheduler_ipi() is inline so can't be passed as callback reason, but the
+ * callsite IP should be sufficient for root-causing IPIs sent from here.
+ */
+#define smp_send_reschedule(cpu) ({ \
+ trace_ipi_send_cpumask(cpumask_of(cpu), _RET_IP_, NULL); \
+ arch_smp_send_reschedule(cpu); \
+})

/*
* Prepare machine for booting other CPUs.
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d255964..7d18896 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -62,11 +62,14 @@
#include "kvm_mm.h"
#include "vfio.h"

+#include <trace/events/ipi.h>
+
#define CREATE_TRACE_POINTS
#include <trace/events/kvm.h>

#include <linux/kvm_dirty_ring.h>

+
/* Worst case buffer size needed for holding an integer. */
#define ITOA_MAX_LEN 12