[patch V2 00/17] init: Enable might_sleep() and smp_processor_id() debugging early

[patch V2 00/17] init: Enable might_sleep() and smp_processor_id() debugging early

[Thomas Gleixner]

We recentlty discovered a call path which takes a mutex from the low level
secondary CPU bringup code and wondered why this was not caught by
might_sleep().

The reason is that both debug facilities depend on system_state ==
SYSTEM_RUNNING, which is set after init memory is freed.

That means that SMP bootup and builtin driver initialization are not
covered by these checks at all.

The patch series addresses this by adding an intermediate state which
enables both debug features right when scheduling starts, i.e. the boot CPU
idle task schedules the first time.

Changes since V1:
	- Use only one new state
	- Enable both debug facilities right before scheduling starts
	- Add more commentry about state ordering and placement of the
          state switch
	- CC ACPI folks on the relevant patch and amend changelog.
	- Collected acks/reviewed-by's

Thanks,

	tglx

[patch V2 01/17] init: Pin init task to boot cpu initially

[Thomas Gleixner]

[-- Attachment #1: init--Pin-init-task-to-boot-cpu-initially.patch --]
[-- Type: text/plain, Size: 2087 bytes --]

Some of the boot code in init_kernel_freeable() which runs before SMP
bringup assumes (rightfully) that it runs on the boot cpu and therefor can
use smp_processor_id() in preemptible context.

That works so far because the smp_processor_id() check starts to be
effective after smp bringup. That's just wrong. Starting with SMP bringup
and the ability to move threads around, smp_processor_id() in preemptible
context is broken.

Aside of that it does not make sense to allow init to run on all cpus
before sched_smp_init() has been run.

Pin the init to the boot cpu so the existing code can continue to use
smp_processor_id() without triggering the checks when the enabling of those
checks starts earlier.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 init/main.c |   17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

--- a/init/main.c
+++ b/init/main.c
@@ -389,6 +389,7 @@ static __initdata DECLARE_COMPLETION(kth
 
 static noinline void __ref rest_init(void)
 {
+	struct task_struct *tsk;
 	int pid;
 
 	rcu_scheduler_starting();
@@ -397,7 +398,17 @@ static noinline void __ref rest_init(voi
 	 * the init task will end up wanting to create kthreads, which, if
 	 * we schedule it before we create kthreadd, will OOPS.
 	 */
-	kernel_thread(kernel_init, NULL, CLONE_FS);
+	pid = kernel_thread(kernel_init, NULL, CLONE_FS);
+	/*
+	 * Pin init on the boot cpu. Task migration is not properly working
+	 * until sched_init_smp() has been run. It will set the allowed
+	 * cpus for init to the non isolated cpus.
+	 */
+	rcu_read_lock();
+	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
+	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
+	rcu_read_unlock();
+
 	numa_default_policy();
 	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
 	rcu_read_lock();
@@ -1015,10 +1026,6 @@ static noinline void __init kernel_init_
 	 * init can allocate pages on any node
 	 */
 	set_mems_allowed(node_states[N_MEMORY]);
-	/*
-	 * init can run on any cpu.
-	 */
-	set_cpus_allowed_ptr(current, cpu_all_mask);
 
 	cad_pid = task_pid(current);
 

[patch V2 02/17] arm: Adjust system_state check

[-- Attachment #1: arm--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 818 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in ipi_cpu_stop() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
---
 arch/arm/kernel/smp.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -555,8 +555,7 @@ static DEFINE_RAW_SPINLOCK(stop_lock);
  */
 static void ipi_cpu_stop(unsigned int cpu)
 {
-	if (system_state == SYSTEM_BOOTING ||
-	    system_state == SYSTEM_RUNNING) {
+	if (system_state <= SYSTEM_RUNNING) {
 		raw_spin_lock(&stop_lock);
 		pr_crit("CPU%u: stopping\n", cpu);
 		dump_stack();

[patch V2 02/17] arm: Adjust system_state check

[Thomas Gleixner]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in ipi_cpu_stop() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel at lists.infradead.org
---
 arch/arm/kernel/smp.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -555,8 +555,7 @@ static DEFINE_RAW_SPINLOCK(stop_lock);
  */
 static void ipi_cpu_stop(unsigned int cpu)
 {
-	if (system_state == SYSTEM_BOOTING ||
-	    system_state == SYSTEM_RUNNING) {
+	if (system_state <= SYSTEM_RUNNING) {
 		raw_spin_lock(&stop_lock);
 		pr_crit("CPU%u: stopping\n", cpu);
 		dump_stack();

[patch V2 03/17] arm64: Adjust system_state check

[Thomas Gleixner]

[-- Attachment #1: arm64--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 939 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in smp_send_stop() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
---
 arch/arm64/kernel/smp.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -961,8 +961,7 @@ void smp_send_stop(void)
 		cpumask_copy(&mask, cpu_online_mask);
 		cpumask_clear_cpu(smp_processor_id(), &mask);
 
-		if (system_state == SYSTEM_BOOTING ||
-		    system_state == SYSTEM_RUNNING)
+		if (system_state <= SYSTEM_RUNNING)
 			pr_crit("SMP: stopping secondary CPUs\n");
 		smp_cross_call(&mask, IPI_CPU_STOP);
 	}

[patch V2 03/17] arm64: Adjust system_state check

[Thomas Gleixner]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in smp_send_stop() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel at lists.infradead.org
---
 arch/arm64/kernel/smp.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -961,8 +961,7 @@ void smp_send_stop(void)
 		cpumask_copy(&mask, cpu_online_mask);
 		cpumask_clear_cpu(smp_processor_id(), &mask);
 
-		if (system_state == SYSTEM_BOOTING ||
-		    system_state == SYSTEM_RUNNING)
+		if (system_state <= SYSTEM_RUNNING)
 			pr_crit("SMP: stopping secondary CPUs\n");
 		smp_cross_call(&mask, IPI_CPU_STOP);
 	}

[patch V2 04/17] x86/smp: Adjust system_state check

[Thomas Gleixner]

[-- Attachment #1: x86-smp--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 785 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in announce_cpu() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 arch/x86/kernel/smpboot.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -863,7 +863,7 @@ static void announce_cpu(int cpu, int ap
 	if (cpu == 1)
 		printk(KERN_INFO "x86: Booting SMP configuration:\n");
 
-	if (system_state == SYSTEM_BOOTING) {
+	if (system_state < SYSTEM_RUNNING) {
 		if (node != current_node) {
 			if (current_node > (-1))
 				pr_cont("\n");

[patch V2 05/17] metag: Adjust system_state check

[Thomas Gleixner]

[-- Attachment #1: metag--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 805 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in stop_this_cpu() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
---
 arch/metag/kernel/smp.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/arch/metag/kernel/smp.c
+++ b/arch/metag/kernel/smp.c
@@ -567,8 +567,7 @@ static void stop_this_cpu(void *data)
 {
 	unsigned int cpu = smp_processor_id();
 
-	if (system_state == SYSTEM_BOOTING ||
-	    system_state == SYSTEM_RUNNING) {
+	if (system_state <= SYSTEM_RUNNING) {
 		spin_lock(&stop_lock);
 		pr_crit("CPU%u: stopping\n", cpu);
 		dump_stack();

[patch V2 06/17] powerpc: Adjust system_state check

[Thomas Gleixner]

[-- Attachment #1: powerpc--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 1023 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in smp_generic_cpu_bootable() to handle the
extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/kernel/smp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -97,7 +97,7 @@ int smp_generic_cpu_bootable(unsigned in
 	/* Special case - we inhibit secondary thread startup
 	 * during boot if the user requests it.
 	 */
-	if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
+	if (system_state < SYSTEM_RUNNING && cpu_has_feature(CPU_FTR_SMT)) {
 		if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
 			return 0;
 		if (smt_enabled_at_boot

[patch V2 06/17] powerpc: Adjust system_state check

[Thomas Gleixner]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in smp_generic_cpu_bootable() to handle the
extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/kernel/smp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -97,7 +97,7 @@ int smp_generic_cpu_bootable(unsigned in
 	/* Special case - we inhibit secondary thread startup
 	 * during boot if the user requests it.
 	 */
-	if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
+	if (system_state < SYSTEM_RUNNING && cpu_has_feature(CPU_FTR_SMT)) {
 		if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
 			return 0;
 		if (smt_enabled_at_boot

[patch V2 07/17] ACPI: Adjust system_state check

[Thomas Gleixner]

[-- Attachment #1: ACPI--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 999 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Make the decision whether a pci root is hotplugged depend on SYSTEM_RUNNING
instead of !SYSTEM_BOOTING. It makes no sense to cover states greater than
SYSTEM_RUNNING as there are not hotplug events on reboot and poweroff.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
---
 drivers/acpi/pci_root.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -523,7 +523,7 @@ static int acpi_pci_root_add(struct acpi
 	struct acpi_pci_root *root;
 	acpi_handle handle = device->handle;
 	int no_aspm = 0;
-	bool hotadd = system_state != SYSTEM_BOOTING;
+	bool hotadd = system_state == SYSTEM_RUNNING;
 
 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 	if (!root)

[patch V2 08/17] mm: Adjust system_state check

[Thomas Gleixner]

[-- Attachment #1: mm--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 1079 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

get_nid_for_pfn() checks for system_state == BOOTING to decide whether to
use early_pfn_to_nid() when CONFIG_DEFERRED_STRUCT_PAGE_INIT=y.

That check is dubious, because the switch to state RUNNING happes way after
page_alloc_init_late() has been invoked.

Change the check to less than RUNNING state so it covers the new
intermediate states as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
---
 drivers/base/node.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -377,7 +377,7 @@ static int __ref get_nid_for_pfn(unsigne
 	if (!pfn_valid_within(pfn))
 		return -1;
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
-	if (system_state == SYSTEM_BOOTING)
+	if (system_state < SYSTEM_RUNNING)
 		return early_pfn_to_nid(pfn);
 #endif
 	page = pfn_to_page(pfn);

[patch V2 09/17] cpufreq/pasemi: Adjust system_state check

[Thomas Gleixner]

[-- Attachment #1: cpufreq-pasemi--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 875 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in pas_cpufreq_cpu_exit() to handle the extra
states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: linuxppc-dev@lists.ozlabs.org
---
 drivers/cpufreq/pasemi-cpufreq.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/cpufreq/pasemi-cpufreq.c
+++ b/drivers/cpufreq/pasemi-cpufreq.c
@@ -226,7 +226,7 @@ static int pas_cpufreq_cpu_exit(struct c
 	 * We don't support CPU hotplug. Don't unmap after the system
 	 * has already made it to a running state.
 	 */
-	if (system_state != SYSTEM_BOOTING)
+	if (system_state >= SYSTEM_RUNNING)
 		return 0;
 
 	if (sdcasr_mapbase)

[patch V2 09/17] cpufreq/pasemi: Adjust system_state check

[Thomas Gleixner]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in pas_cpufreq_cpu_exit() to handle the extra
states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: linuxppc-dev@lists.ozlabs.org
---
 drivers/cpufreq/pasemi-cpufreq.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/cpufreq/pasemi-cpufreq.c
+++ b/drivers/cpufreq/pasemi-cpufreq.c
@@ -226,7 +226,7 @@ static int pas_cpufreq_cpu_exit(struct c
 	 * We don't support CPU hotplug. Don't unmap after the system
 	 * has already made it to a running state.
 	 */
-	if (system_state != SYSTEM_BOOTING)
+	if (system_state >= SYSTEM_RUNNING)
 		return 0;
 
 	if (sdcasr_mapbase)

[patch V2 10/17] iommu/vt-d: Adjust system_state checks

[Thomas Gleixner]

[-- Attachment #1: iommu-vt-d--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 1260 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state checks in dmar_parse_one_atsr() and
dmar_iommu_notify_scope_dev() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Joerg Roedel <joro@8bytes.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: iommu@lists.linux-foundation.org
---
 drivers/iommu/intel-iommu.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4312,7 +4312,7 @@ int dmar_parse_one_atsr(struct acpi_dmar
 	struct acpi_dmar_atsr *atsr;
 	struct dmar_atsr_unit *atsru;
 
-	if (system_state != SYSTEM_BOOTING && !intel_iommu_enabled)
+	if (system_state >= SYSTEM_RUNNING && !intel_iommu_enabled)
 		return 0;
 
 	atsr = container_of(hdr, struct acpi_dmar_atsr, header);
@@ -4562,7 +4562,7 @@ int dmar_iommu_notify_scope_dev(struct d
 	struct acpi_dmar_atsr *atsr;
 	struct acpi_dmar_reserved_memory *rmrr;
 
-	if (!intel_iommu_enabled && system_state != SYSTEM_BOOTING)
+	if (!intel_iommu_enabled && system_state >= SYSTEM_RUNNING)
 		return 0;
 
 	list_for_each_entry(rmrru, &dmar_rmrr_units, list) {

[patch V2 10/17] iommu/vt-d: Adjust system_state checks

[Thomas Gleixner]

[-- Attachment #1: iommu-vt-d--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 1375 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state checks in dmar_parse_one_atsr() and
dmar_iommu_notify_scope_dev() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Acked-by: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
Cc: David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
---
 drivers/iommu/intel-iommu.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4312,7 +4312,7 @@ int dmar_parse_one_atsr(struct acpi_dmar
 	struct acpi_dmar_atsr *atsr;
 	struct dmar_atsr_unit *atsru;
 
-	if (system_state != SYSTEM_BOOTING && !intel_iommu_enabled)
+	if (system_state >= SYSTEM_RUNNING && !intel_iommu_enabled)
 		return 0;
 
 	atsr = container_of(hdr, struct acpi_dmar_atsr, header);
@@ -4562,7 +4562,7 @@ int dmar_iommu_notify_scope_dev(struct d
 	struct acpi_dmar_atsr *atsr;
 	struct acpi_dmar_reserved_memory *rmrr;
 
-	if (!intel_iommu_enabled && system_state != SYSTEM_BOOTING)
+	if (!intel_iommu_enabled && system_state >= SYSTEM_RUNNING)
 		return 0;
 
 	list_for_each_entry(rmrru, &dmar_rmrr_units, list) {

[patch V2 11/17] iommu/of: Adjust system_state check

[Thomas Gleixner]

[-- Attachment #1: iommu-of--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 902 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in of_iommu_driver_present() to handle the
extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Cc: iommu@lists.linux-foundation.org
---
 drivers/iommu/of_iommu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -103,7 +103,7 @@ static bool of_iommu_driver_present(stru
 	 * it never will be. We don't want to defer indefinitely, nor attempt
 	 * to dereference __iommu_of_table after it's been freed.
 	 */
-	if (system_state > SYSTEM_BOOTING)
+	if (system_state >= SYSTEM_RUNNING)
 		return false;
 
 	return of_match_node(&__iommu_of_table, np);

[patch V2 11/17] iommu/of: Adjust system_state check

[Thomas Gleixner]

[-- Attachment #1: iommu-of--Adjust-system_state-check.patch --]
[-- Type: text/plain, Size: 1012 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in of_iommu_driver_present() to handle the
extra states.

Signed-off-by: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Acked-by: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
Acked-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
---
 drivers/iommu/of_iommu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -103,7 +103,7 @@ static bool of_iommu_driver_present(stru
 	 * it never will be. We don't want to defer indefinitely, nor attempt
 	 * to dereference __iommu_of_table after it's been freed.
 	 */
-	if (system_state > SYSTEM_BOOTING)
+	if (system_state >= SYSTEM_RUNNING)
 		return false;
 
 	return of_match_node(&__iommu_of_table, np);

[patch V2 12/17] async: Adjust system_state checks

[Thomas Gleixner]

[-- Attachment #1: async--Adjust-system_state-checks.patch --]
[-- Type: text/plain, Size: 1783 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in async_run_entry_fn() and
async_synchronize_cookie_domain() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
---
 kernel/async.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/kernel/async.c
+++ b/kernel/async.c
@@ -114,14 +114,14 @@ static void async_run_entry_fn(struct wo
 	ktime_t uninitialized_var(calltime), delta, rettime;
 
 	/* 1) run (and print duration) */
-	if (initcall_debug && system_state == SYSTEM_BOOTING) {
+	if (initcall_debug && system_state < SYSTEM_RUNNING) {
 		pr_debug("calling  %lli_%pF @ %i\n",
 			(long long)entry->cookie,
 			entry->func, task_pid_nr(current));
 		calltime = ktime_get();
 	}
 	entry->func(entry->data, entry->cookie);
-	if (initcall_debug && system_state == SYSTEM_BOOTING) {
+	if (initcall_debug && system_state < SYSTEM_RUNNING) {
 		rettime = ktime_get();
 		delta = ktime_sub(rettime, calltime);
 		pr_debug("initcall %lli_%pF returned 0 after %lld usecs\n",
@@ -284,14 +284,14 @@ void async_synchronize_cookie_domain(asy
 {
 	ktime_t uninitialized_var(starttime), delta, endtime;
 
-	if (initcall_debug && system_state == SYSTEM_BOOTING) {
+	if (initcall_debug && system_state < SYSTEM_RUNNING) {
 		pr_debug("async_waiting @ %i\n", task_pid_nr(current));
 		starttime = ktime_get();
 	}
 
 	wait_event(async_done, lowest_in_progress(domain) >= cookie);
 
-	if (initcall_debug && system_state == SYSTEM_BOOTING) {
+	if (initcall_debug && system_state < SYSTEM_RUNNING) {
 		endtime = ktime_get();
 		delta = ktime_sub(endtime, starttime);
 

[patch V2 13/17] extable: Adjust system_state checks

[Thomas Gleixner]

[-- Attachment #1: extable--Adjust-system_state-checks.patch --]
[-- Type: text/plain, Size: 794 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in core_kernel_text() to handle the extra
states, i.e. to cover init text up to the point where the system switches
to state RUNNING.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/extable.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -75,7 +75,7 @@ int core_kernel_text(unsigned long addr)
 	    addr < (unsigned long)_etext)
 		return 1;
 
-	if (system_state == SYSTEM_BOOTING &&
+	if (system_state < SYSTEM_RUNNING &&
 	    init_kernel_text(addr))
 		return 1;
 	return 0;

[patch V2 14/17] printk: Adjust system_state checks

[Thomas Gleixner]

[-- Attachment #1: printk--Adjust-system_state-checks.patch --]
[-- Type: text/plain, Size: 768 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in boot_delay_msec() to handle the extra
states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/printk/printk.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1176,7 +1176,7 @@ static void boot_delay_msec(int level)
 	unsigned long long k;
 	unsigned long timeout;
 
-	if ((boot_delay == 0 || system_state != SYSTEM_BOOTING)
+	if ((boot_delay == 0 || system_state >= SYSTEM_RUNNING)
 		|| suppress_message_printing(level)) {
 		return;
 	}

[patch V2 15/17] mm/vmscan: Adjust system_state checks

[Thomas Gleixner]

[-- Attachment #1: mm-vmscan--Adjust-system_state-checks.patch --]
[-- Type: text/plain, Size: 1044 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in kswapd_run() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: linux-mm@kvack.org
---
 mm/vmscan.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3643,7 +3643,7 @@ int kswapd_run(int nid)
 	pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);
 	if (IS_ERR(pgdat->kswapd)) {
 		/* failure at boot is fatal */
-		BUG_ON(system_state == SYSTEM_BOOTING);
+		BUG_ON(system_state < SYSTEM_RUNNING);
 		pr_err("Failed to start kswapd on node %d\n", nid);
 		ret = PTR_ERR(pgdat->kswapd);
 		pgdat->kswapd = NULL;

[patch V2 15/17] mm/vmscan: Adjust system_state checks

[Thomas Gleixner]

[-- Attachment #1: mm-vmscan--Adjust-system_state-checks.patch --]
[-- Type: text/plain, Size: 1271 bytes --]

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in kswapd_run() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: linux-mm@kvack.org
---
 mm/vmscan.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3643,7 +3643,7 @@ int kswapd_run(int nid)
 	pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);
 	if (IS_ERR(pgdat->kswapd)) {
 		/* failure at boot is fatal */
-		BUG_ON(system_state == SYSTEM_BOOTING);
+		BUG_ON(system_state < SYSTEM_RUNNING);
 		pr_err("Failed to start kswapd on node %d\n", nid);
 		ret = PTR_ERR(pgdat->kswapd);
 		pgdat->kswapd = NULL;


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[patch V2 16/17] init: Introduce SYSTEM_SCHEDULING state

[Thomas Gleixner]

[-- Attachment #1: init--Introduce-SYSTEM_SCHEDULING-state.patch --]
[-- Type: text/plain, Size: 1507 bytes --]

might_sleep() debugging and smp_processor_id() debugging should be active
right after the scheduler starts working. The init task can invoke
smp_processor_id() from preemptible context as it is pinned on the boot cpu
until sched_smp_init() removes the pinning and lets it schedule on all non
isolated cpus.

Add a new state which allows to enable those checks earlier and add it to
the xen do_poweroff() function.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

V2: Use only one intermediate state and document that state order matters.

 drivers/xen/manage.c   |    1 +
 include/linux/kernel.h |    6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -190,6 +190,7 @@ static void do_poweroff(void)
 {
 	switch (system_state) {
 	case SYSTEM_BOOTING:
+	case SYSTEM_SCHEDULING:
 		orderly_poweroff(true);
 		break;
 	case SYSTEM_RUNNING:
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -490,9 +490,13 @@ extern int root_mountflags;
 
 extern bool early_boot_irqs_disabled;
 
-/* Values used for system_state */
+/*
+ * Values used for system_state. Ordering of the states must not be changed
+ * as code checks for <, <=, >, >= STATE.
+ */
 extern enum system_states {
 	SYSTEM_BOOTING,
+	SYSTEM_SCHEDULING,
 	SYSTEM_RUNNING,
 	SYSTEM_HALT,
 	SYSTEM_POWER_OFF,

[patch V2 17/17] sched: Enable might_sleep() and smp_processor_id() checks early

[Thomas Gleixner]

[-- Attachment #1: sched--Enable-might_sleep---checks-early.patch --]
[-- Type: text/plain, Size: 1894 bytes --]

might_sleep() and smp_processor_id() checks are enabled after the boot
process is done. That hides bugs in the smp bringup and driver
initialization code.

Enable it right when the scheduler starts working, i.e. when init task and
kthreadd have been created and right before the idle task enables
preemption.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 init/main.c            |   10 ++++++++++
 kernel/sched/core.c    |    4 +++-
 lib/smp_processor_id.c |    2 +-
 3 files changed, 14 insertions(+), 2 deletions(-)

--- a/init/main.c
+++ b/init/main.c
@@ -414,6 +414,16 @@ static noinline void __ref rest_init(voi
 	rcu_read_lock();
 	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
 	rcu_read_unlock();
+
+	/*
+	 * Enable might_sleep() and smp_processor_id() checks.
+	 * They cannot be enabled earlier because with CONFIG_PRREMPT=y
+	 * kernel_thread() would trigger might_sleep() splats. With
+	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
+	 * already, but it's stuck on the kthreadd_done completion.
+	 */
+	system_state = SYSTEM_SCHEDULING;
+
 	complete(&kthreadd_done);
 
 	/*
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6226,8 +6226,10 @@ void ___might_sleep(const char *file, in
 
 	if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
 	     !is_idle_task(current)) ||
-	    system_state != SYSTEM_RUNNING || oops_in_progress)
+	    system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING ||
+	    oops_in_progress)
 		return;
+
 	if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
 		return;
 	prev_jiffy = jiffies;
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -28,7 +28,7 @@ notrace static unsigned int check_preemp
 	/*
 	 * It is valid to assume CPU-locality during early bootup:
 	 */
-	if (system_state != SYSTEM_RUNNING)
+	if (system_state < SYSTEM_SCHEDULING)
 		goto out;
 
 	/*

Re: [patch V2 01/17] init: Pin init task to boot cpu initially

[Steven Rostedt]

On Tue, 16 May 2017 20:42:32 +0200
Thomas Gleixner <tglx@linutronix.de> wrote:

> Some of the boot code in init_kernel_freeable() which runs before SMP
> bringup assumes (rightfully) that it runs on the boot cpu and therefor can
> use smp_processor_id() in preemptible context.
> 
> That works so far because the smp_processor_id() check starts to be
> effective after smp bringup. That's just wrong. Starting with SMP bringup
> and the ability to move threads around, smp_processor_id() in preemptible
> context is broken.
> 
> Aside of that it does not make sense to allow init to run on all cpus
> before sched_smp_init() has been run.
> 
> Pin the init to the boot cpu so the existing code can continue to use
> smp_processor_id() without triggering the checks when the enabling of those
> checks starts earlier.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
>  init/main.c |   17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> --- a/init/main.c
> +++ b/init/main.c
> @@ -389,6 +389,7 @@ static __initdata DECLARE_COMPLETION(kth
>  
>  static noinline void __ref rest_init(void)
>  {
> +	struct task_struct *tsk;
>  	int pid;
>  
>  	rcu_scheduler_starting();
> @@ -397,7 +398,17 @@ static noinline void __ref rest_init(voi
>  	 * the init task will end up wanting to create kthreads, which, if
>  	 * we schedule it before we create kthreadd, will OOPS.
>  	 */
> -	kernel_thread(kernel_init, NULL, CLONE_FS);
> +	pid = kernel_thread(kernel_init, NULL, CLONE_FS);
> +	/*
> +	 * Pin init on the boot cpu. Task migration is not properly working
> +	 * until sched_init_smp() has been run. It will set the allowed
> +	 * cpus for init to the non isolated cpus.
> +	 */
> +	rcu_read_lock();
> +	tsk = find_task_by_pid_ns(pid, &init_pid_ns);

Should we have a:

	BUG_ON(!tsk);

Just to be paranoid?

-- Steve

> +	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
> +	rcu_read_unlock();
> +
>  	numa_default_policy();
>  	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
>  	rcu_read_lock();
> @@ -1015,10 +1026,6 @@ static noinline void __init kernel_init_
>  	 * init can allocate pages on any node
>  	 */
>  	set_mems_allowed(node_states[N_MEMORY]);
> -	/*
> -	 * init can run on any cpu.
> -	 */
> -	set_cpus_allowed_ptr(current, cpu_all_mask);
>  
>  	cad_pid = task_pid(current);
>  
> 

Re: [patch V2 07/17] ACPI: Adjust system_state check

[Steven Rostedt]

On Tue, 16 May 2017 20:42:38 +0200
Thomas Gleixner <tglx@linutronix.de> wrote:

> To enable smp_processor_id() and might_sleep() debug checks earlier, it's
> required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
> 
> Make the decision whether a pci root is hotplugged depend on SYSTEM_RUNNING
> instead of !SYSTEM_BOOTING. It makes no sense to cover states greater than
> SYSTEM_RUNNING as there are not hotplug events on reboot and poweroff.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

-- Steve

> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Len Brown <lenb@kernel.org>
> Cc: linux-acpi@vger.kernel.org
> ---
>  drivers/acpi/pci_root.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -523,7 +523,7 @@ static int acpi_pci_root_add(struct acpi
>  	struct acpi_pci_root *root;
>  	acpi_handle handle = device->handle;
>  	int no_aspm = 0;
> -	bool hotadd = system_state != SYSTEM_BOOTING;
> +	bool hotadd = system_state == SYSTEM_RUNNING;
>  
>  	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
>  	if (!root)
> 

Re: [patch V2 17/17] sched: Enable might_sleep() and smp_processor_id() checks early

[Steven Rostedt]

On Tue, 16 May 2017 20:42:48 +0200
Thomas Gleixner <tglx@linutronix.de> wrote:

> might_sleep() and smp_processor_id() checks are enabled after the boot
> process is done. That hides bugs in the smp bringup and driver
> initialization code.
> 
> Enable it right when the scheduler starts working, i.e. when init task and
> kthreadd have been created and right before the idle task enables
> preemption.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
>  init/main.c            |   10 ++++++++++
>  kernel/sched/core.c    |    4 +++-
>  lib/smp_processor_id.c |    2 +-
>  3 files changed, 14 insertions(+), 2 deletions(-)
> 
> --- a/init/main.c
> +++ b/init/main.c
> @@ -414,6 +414,16 @@ static noinline void __ref rest_init(voi
>  	rcu_read_lock();
>  	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
>  	rcu_read_unlock();
> +
> +	/*
> +	 * Enable might_sleep() and smp_processor_id() checks.
> +	 * They cannot be enabled earlier because with CONFIG_PRREMPT=y

My cat's version of CONFIG_PREEMPT, it's CONFIG_ PRR EMPT!


> +	 * kernel_thread() would trigger might_sleep() splats. With
> +	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
> +	 * already, but it's stuck on the kthreadd_done completion.
> +	 */
> +	system_state = SYSTEM_SCHEDULING;
> +
>  	complete(&kthreadd_done);
>  
>  	/*
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -6226,8 +6226,10 @@ void ___might_sleep(const char *file, in
>  
>  	if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
>  	     !is_idle_task(current)) ||
> -	    system_state != SYSTEM_RUNNING || oops_in_progress)
> +	    system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING ||
> +	    oops_in_progress)
>  		return;
> +
>  	if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
>  		return;
>  	prev_jiffy = jiffies;
> --- a/lib/smp_processor_id.c
> +++ b/lib/smp_processor_id.c
> @@ -28,7 +28,7 @@ notrace static unsigned int check_preemp
>  	/*
>  	 * It is valid to assume CPU-locality during early bootup:
>  	 */
> -	if (system_state != SYSTEM_RUNNING)
> +	if (system_state < SYSTEM_SCHEDULING)

Do we want to ignore halting or rebooting too?

-- Steve

>  		goto out;
>  
>  	/*
> 

Re: [patch V2 17/17] sched: Enable might_sleep() and smp_processor_id() checks early

[Thomas Gleixner]

On Tue, 16 May 2017, Steven Rostedt wrote:
> On Tue, 16 May 2017 20:42:48 +0200
> Thomas Gleixner <tglx@linutronix.de> wrote:
> > +
> > +	/*
> > +	 * Enable might_sleep() and smp_processor_id() checks.
> > +	 * They cannot be enabled earlier because with CONFIG_PRREMPT=y
> 
> My cat's version of CONFIG_PREEMPT, it's CONFIG_ PRR EMPT!

I don't have a cat and I don't need one for creating typos. I'm perfectly
able to do that myself :)

> > +	 * kernel_thread() would trigger might_sleep() splats. With
> > +	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
> > +	 * already, but it's stuck on the kthreadd_done completion.
> > +	 */
> > +	system_state = SYSTEM_SCHEDULING;
> > +
> >  	complete(&kthreadd_done);
> >  
> >  	/*
> > --- a/kernel/sched/core.c
> > +++ b/kernel/sched/core.c
> > @@ -6226,8 +6226,10 @@ void ___might_sleep(const char *file, in
> >  
> >  	if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
> >  	     !is_idle_task(current)) ||
> > -	    system_state != SYSTEM_RUNNING || oops_in_progress)
> > +	    system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING ||
> > +	    oops_in_progress)
> >  		return;
> > +
> >  	if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
> >  		return;
> >  	prev_jiffy = jiffies;
> > --- a/lib/smp_processor_id.c
> > +++ b/lib/smp_processor_id.c
> > @@ -28,7 +28,7 @@ notrace static unsigned int check_preemp
> >  	/*
> >  	 * It is valid to assume CPU-locality during early bootup:
> >  	 */
> > -	if (system_state != SYSTEM_RUNNING)
> > +	if (system_state < SYSTEM_SCHEDULING)
> 
> Do we want to ignore halting or rebooting too?

I don't think so. After setting those states, interesting stuff like
device_shutdown() gets invoked. We want the coverage there.

Thanks,

	tglx

Re: [patch V2 17/17] sched: Enable might_sleep() and smp_processor_id() checks early

[Steven Rostedt]

On Wed, 17 May 2017 00:46:37 +0200 (CEST)
Thomas Gleixner <tglx@linutronix.de> wrote:


> > > --- a/lib/smp_processor_id.c
> > > +++ b/lib/smp_processor_id.c
> > > @@ -28,7 +28,7 @@ notrace static unsigned int check_preemp
> > >  	/*
> > >  	 * It is valid to assume CPU-locality during early bootup:
> > >  	 */
> > > -	if (system_state != SYSTEM_RUNNING)
> > > +	if (system_state < SYSTEM_SCHEDULING)  
> > 
> > Do we want to ignore halting or rebooting too?  
> 
> I don't think so. After setting those states, interesting stuff like
> device_shutdown() gets invoked. We want the coverage there.

Then I'd suggest that you update the change log, as this patch also
adds coverage to those states as well.

-- Steve

Re: [patch V2 15/17] mm/vmscan: Adjust system_state checks

[Vlastimil Babka]

On 05/16/2017 08:42 PM, Thomas Gleixner wrote:
> To enable smp_processor_id() and might_sleep() debug checks earlier, it's
> required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
> 
> Adjust the system_state check in kswapd_run() to handle the extra states.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Mel Gorman <mgorman@techsingularity.net>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: linux-mm@kvack.org

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  mm/vmscan.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -3643,7 +3643,7 @@ int kswapd_run(int nid)
>  	pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);
>  	if (IS_ERR(pgdat->kswapd)) {
>  		/* failure at boot is fatal */
> -		BUG_ON(system_state == SYSTEM_BOOTING);
> +		BUG_ON(system_state < SYSTEM_RUNNING);
>  		pr_err("Failed to start kswapd on node %d\n", nid);
>  		ret = PTR_ERR(pgdat->kswapd);
>  		pgdat->kswapd = NULL;
> 
> 

Re: [patch V2 15/17] mm/vmscan: Adjust system_state checks

[Vlastimil Babka]

On 05/16/2017 08:42 PM, Thomas Gleixner wrote:
> To enable smp_processor_id() and might_sleep() debug checks earlier, it's
> required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
> 
> Adjust the system_state check in kswapd_run() to handle the extra states.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Mel Gorman <mgorman@techsingularity.net>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: linux-mm@kvack.org

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  mm/vmscan.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -3643,7 +3643,7 @@ int kswapd_run(int nid)
>  	pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);
>  	if (IS_ERR(pgdat->kswapd)) {
>  		/* failure at boot is fatal */
> -		BUG_ON(system_state == SYSTEM_BOOTING);
> +		BUG_ON(system_state < SYSTEM_RUNNING);
>  		pr_err("Failed to start kswapd on node %d\n", nid);
>  		ret = PTR_ERR(pgdat->kswapd);
>  		pgdat->kswapd = NULL;
> 
> 

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Re: [patch V2 03/17] arm64: Adjust system_state check

[Mark Rutland]

On Tue, May 16, 2017 at 08:42:34PM +0200, Thomas Gleixner wrote:
> To enable smp_processor_id() and might_sleep() debug checks earlier, it's
> required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
> 
> Adjust the system_state check in smp_send_stop() to handle the extra states.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-arm-kernel@lists.infradead.org
> ---
>  arch/arm64/kernel/smp.c |    3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

FWIW:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

> 
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -961,8 +961,7 @@ void smp_send_stop(void)
>  		cpumask_copy(&mask, cpu_online_mask);
>  		cpumask_clear_cpu(smp_processor_id(), &mask);
>  
> -		if (system_state == SYSTEM_BOOTING ||
> -		    system_state == SYSTEM_RUNNING)
> +		if (system_state <= SYSTEM_RUNNING)
>  			pr_crit("SMP: stopping secondary CPUs\n");
>  		smp_cross_call(&mask, IPI_CPU_STOP);
>  	}
> 
> 

[patch V2 03/17] arm64: Adjust system_state check

[Mark Rutland]

On Tue, May 16, 2017 at 08:42:34PM +0200, Thomas Gleixner wrote:
> To enable smp_processor_id() and might_sleep() debug checks earlier, it's
> required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
> 
> Adjust the system_state check in smp_send_stop() to handle the extra states.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-arm-kernel at lists.infradead.org
> ---
>  arch/arm64/kernel/smp.c |    3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

FWIW:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

> 
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -961,8 +961,7 @@ void smp_send_stop(void)
>  		cpumask_copy(&mask, cpu_online_mask);
>  		cpumask_clear_cpu(smp_processor_id(), &mask);
>  
> -		if (system_state == SYSTEM_BOOTING ||
> -		    system_state == SYSTEM_RUNNING)
> +		if (system_state <= SYSTEM_RUNNING)
>  			pr_crit("SMP: stopping secondary CPUs\n");
>  		smp_cross_call(&mask, IPI_CPU_STOP);
>  	}
> 
> 

Re: [patch V2 00/17] init: Enable might_sleep() and smp_processor_id() debugging early

[Mark Rutland]

Hi,

On Tue, May 16, 2017 at 08:42:31PM +0200, Thomas Gleixner wrote:
> We recentlty discovered a call path which takes a mutex from the low level
> secondary CPU bringup code and wondered why this was not caught by
> might_sleep().
> 
> The reason is that both debug facilities depend on system_state ==
> SYSTEM_RUNNING, which is set after init memory is freed.
> 
> That means that SMP bootup and builtin driver initialization are not
> covered by these checks at all.
> 
> The patch series addresses this by adding an intermediate state which
> enables both debug features right when scheduling starts, i.e. the boot CPU
> idle task schedules the first time.

Thanks again for attacking this.

I gave this a spin atop of v4.12-rc1 on an ARM Juno platform. It picks
up the mutex issue, and I see no other new warnings. With a fix [1] for
the mutex issue appplied, I see no warnings.

Feel free to add my Tested-by for the arm64 and common bits.

Thanks,
Mark.

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-May/506558.html

Re: [patch V2 16/17] init: Introduce SYSTEM_SCHEDULING state

[Mark Rutland]

On Tue, May 16, 2017 at 08:42:47PM +0200, Thomas Gleixner wrote:
> might_sleep() debugging and smp_processor_id() debugging should be active
> right after the scheduler starts working. The init task can invoke
> smp_processor_id() from preemptible context as it is pinned on the boot cpu
> until sched_smp_init() removes the pinning and lets it schedule on all non
> isolated cpus.
> 
> Add a new state which allows to enable those checks earlier and add it to
> the xen do_poweroff() function.
> 
> No functional change.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: Juergen Gross <jgross@suse.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Makes sense to me. FWIW:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

> ---
> 
> V2: Use only one intermediate state and document that state order matters.
> 
>  drivers/xen/manage.c   |    1 +
>  include/linux/kernel.h |    6 +++++-
>  2 files changed, 6 insertions(+), 1 deletion(-)
> 
> --- a/drivers/xen/manage.c
> +++ b/drivers/xen/manage.c
> @@ -190,6 +190,7 @@ static void do_poweroff(void)
>  {
>  	switch (system_state) {
>  	case SYSTEM_BOOTING:
> +	case SYSTEM_SCHEDULING:
>  		orderly_poweroff(true);
>  		break;
>  	case SYSTEM_RUNNING:
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -490,9 +490,13 @@ extern int root_mountflags;
>  
>  extern bool early_boot_irqs_disabled;
>  
> -/* Values used for system_state */
> +/*
> + * Values used for system_state. Ordering of the states must not be changed
> + * as code checks for <, <=, >, >= STATE.
> + */
>  extern enum system_states {
>  	SYSTEM_BOOTING,
> +	SYSTEM_SCHEDULING,
>  	SYSTEM_RUNNING,
>  	SYSTEM_HALT,
>  	SYSTEM_POWER_OFF,
> 
> 

Re: [patch V2 17/17] sched: Enable might_sleep() and smp_processor_id() checks early

[Mark Rutland]

On Tue, May 16, 2017 at 08:42:48PM +0200, Thomas Gleixner wrote:
> might_sleep() and smp_processor_id() checks are enabled after the boot
> process is done. That hides bugs in the smp bringup and driver
> initialization code.
> 
> Enable it right when the scheduler starts working, i.e. when init task and
> kthreadd have been created and right before the idle task enables
> preemption.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Modulo Steve's comments, FWIW:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

> ---
>  init/main.c            |   10 ++++++++++
>  kernel/sched/core.c    |    4 +++-
>  lib/smp_processor_id.c |    2 +-
>  3 files changed, 14 insertions(+), 2 deletions(-)
> 
> --- a/init/main.c
> +++ b/init/main.c
> @@ -414,6 +414,16 @@ static noinline void __ref rest_init(voi
>  	rcu_read_lock();
>  	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
>  	rcu_read_unlock();
> +
> +	/*
> +	 * Enable might_sleep() and smp_processor_id() checks.
> +	 * They cannot be enabled earlier because with CONFIG_PRREMPT=y
> +	 * kernel_thread() would trigger might_sleep() splats. With
> +	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
> +	 * already, but it's stuck on the kthreadd_done completion.
> +	 */
> +	system_state = SYSTEM_SCHEDULING;
> +
>  	complete(&kthreadd_done);
>  
>  	/*
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -6226,8 +6226,10 @@ void ___might_sleep(const char *file, in
>  
>  	if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
>  	     !is_idle_task(current)) ||
> -	    system_state != SYSTEM_RUNNING || oops_in_progress)
> +	    system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING ||
> +	    oops_in_progress)
>  		return;
> +
>  	if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
>  		return;
>  	prev_jiffy = jiffies;
> --- a/lib/smp_processor_id.c
> +++ b/lib/smp_processor_id.c
> @@ -28,7 +28,7 @@ notrace static unsigned int check_preemp
>  	/*
>  	 * It is valid to assume CPU-locality during early bootup:
>  	 */
> -	if (system_state != SYSTEM_RUNNING)
> +	if (system_state < SYSTEM_SCHEDULING)
>  		goto out;
>  
>  	/*
> 
> 

Re: [patch V2 03/17] arm64: Adjust system_state check

[Catalin Marinas]

On Tue, May 16, 2017 at 08:42:34PM +0200, Thomas Gleixner wrote:
> To enable smp_processor_id() and might_sleep() debug checks earlier, it's
> required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
> 
> Adjust the system_state check in smp_send_stop() to handle the extra states.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-arm-kernel@lists.infradead.org

Acked-by: Catalin Marinas <catalin.marinas@arm.com>

[patch V2 03/17] arm64: Adjust system_state check

[Catalin Marinas]

On Tue, May 16, 2017 at 08:42:34PM +0200, Thomas Gleixner wrote:
> To enable smp_processor_id() and might_sleep() debug checks earlier, it's
> required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
> 
> Adjust the system_state check in smp_send_stop() to handle the extra states.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-arm-kernel at lists.infradead.org

Acked-by: Catalin Marinas <catalin.marinas@arm.com>

Re: [patch V2 16/17] init: Introduce SYSTEM_SCHEDULING state

[Boris Ostrovsky]

On 05/16/2017 02:42 PM, Thomas Gleixner wrote:
> might_sleep() debugging and smp_processor_id() debugging should be active
> right after the scheduler starts working. The init task can invoke
> smp_processor_id() from preemptible context as it is pinned on the boot cpu
> until sched_smp_init() removes the pinning and lets it schedule on all non
> isolated cpus.
>
> Add a new state which allows to enable those checks earlier and add it to
> the xen do_poweroff() function.
>
> No functional change.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: Juergen Gross <jgross@suse.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

[tip:sched/core] init: Pin init task to the boot CPU, initially

[tip-bot for Thomas Gleixner]

Commit-ID:  8fb12156b8db61af3d49f3e5e104568494581d1f
Gitweb:     http://git.kernel.org/tip/8fb12156b8db61af3d49f3e5e104568494581d1f
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:32 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:34 +0200

init: Pin init task to the boot CPU, initially

Some of the boot code in init_kernel_freeable() which runs before SMP
bringup assumes (rightfully) that it runs on the boot CPU and therefore can
use smp_processor_id() in preemptible context.

That works so far because the smp_processor_id() check starts to be
effective after smp bringup. That's just wrong. Starting with SMP bringup
and the ability to move threads around, smp_processor_id() in preemptible
context is broken.

Aside of that it does not make sense to allow init to run on all CPUs
before sched_smp_init() has been run.

Pin the init to the boot CPU so the existing code can continue to use
smp_processor_id() without triggering the checks when the enabling of those
checks starts earlier.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184734.943149935@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 init/main.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/init/main.c b/init/main.c
index f866510..badae3b 100644
--- a/init/main.c
+++ b/init/main.c
@@ -389,6 +389,7 @@ static __initdata DECLARE_COMPLETION(kthreadd_done);
 
 static noinline void __ref rest_init(void)
 {
+	struct task_struct *tsk;
 	int pid;
 
 	rcu_scheduler_starting();
@@ -397,7 +398,17 @@ static noinline void __ref rest_init(void)
 	 * the init task will end up wanting to create kthreads, which, if
 	 * we schedule it before we create kthreadd, will OOPS.
 	 */
-	kernel_thread(kernel_init, NULL, CLONE_FS);
+	pid = kernel_thread(kernel_init, NULL, CLONE_FS);
+	/*
+	 * Pin init on the boot CPU. Task migration is not properly working
+	 * until sched_init_smp() has been run. It will set the allowed
+	 * CPUs for init to the non isolated CPUs.
+	 */
+	rcu_read_lock();
+	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
+	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
+	rcu_read_unlock();
+
 	numa_default_policy();
 	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
 	rcu_read_lock();
@@ -1015,10 +1026,6 @@ static noinline void __init kernel_init_freeable(void)
 	 * init can allocate pages on any node
 	 */
 	set_mems_allowed(node_states[N_MEMORY]);
-	/*
-	 * init can run on any cpu.
-	 */
-	set_cpus_allowed_ptr(current, cpu_all_mask);
 
 	cad_pid = task_pid(current);
 

[tip:sched/core] arm: Adjust system_state check

[tip-bot for Thomas Gleixner]

Commit-ID:  5976a66913a8bf42465d96776fd37fb5631edc19
Gitweb:     http://git.kernel.org/tip/5976a66913a8bf42465d96776fd37fb5631edc19
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:33 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:35 +0200

arm: Adjust system_state check

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in ipi_cpu_stop() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20170516184735.020718977@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/arm/kernel/smp.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 572a8df..c9a0a52 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -555,8 +555,7 @@ static DEFINE_RAW_SPINLOCK(stop_lock);
  */
 static void ipi_cpu_stop(unsigned int cpu)
 {
-	if (system_state == SYSTEM_BOOTING ||
-	    system_state == SYSTEM_RUNNING) {
+	if (system_state <= SYSTEM_RUNNING) {
 		raw_spin_lock(&stop_lock);
 		pr_crit("CPU%u: stopping\n", cpu);
 		dump_stack();

[tip:sched/core] arm64: Adjust system_state check

[tip-bot for Thomas Gleixner]

Commit-ID:  ef284f5ca5f102bf855e599305c0c16d6e844635
Gitweb:     http://git.kernel.org/tip/ef284f5ca5f102bf855e599305c0c16d6e844635
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:34 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:35 +0200

arm64: Adjust system_state check

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in smp_send_stop() to handle the extra states.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20170516184735.112589728@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/arm64/kernel/smp.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 6e0e16a..3211198 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -961,8 +961,7 @@ void smp_send_stop(void)
 		cpumask_copy(&mask, cpu_online_mask);
 		cpumask_clear_cpu(smp_processor_id(), &mask);
 
-		if (system_state == SYSTEM_BOOTING ||
-		    system_state == SYSTEM_RUNNING)
+		if (system_state <= SYSTEM_RUNNING)
 			pr_crit("SMP: stopping secondary CPUs\n");
 		smp_cross_call(&mask, IPI_CPU_STOP);
 	}

[tip:sched/core] x86/smp: Adjust system_state check

[tip-bot for Thomas Gleixner]

Commit-ID:  719b3680d1f789c1e3054e3fcb26bfff07c3c623
Gitweb:     http://git.kernel.org/tip/719b3680d1f789c1e3054e3fcb26bfff07c3c623
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:35 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:35 +0200

x86/smp: Adjust system_state check

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in announce_cpu() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170516184735.191715856@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/smpboot.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index f04479a..045e4f9 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -863,7 +863,7 @@ static void announce_cpu(int cpu, int apicid)
 	if (cpu == 1)
 		printk(KERN_INFO "x86: Booting SMP configuration:\n");
 
-	if (system_state == SYSTEM_BOOTING) {
+	if (system_state < SYSTEM_RUNNING) {
 		if (node != current_node) {
 			if (current_node > (-1))
 				pr_cont("\n");

[tip:sched/core] metag: Adjust system_state check

[tip-bot for Thomas Gleixner]

Commit-ID:  dcd2e4734b428709984e2fa35ebbd6cccc246d47
Gitweb:     http://git.kernel.org/tip/dcd2e4734b428709984e2fa35ebbd6cccc246d47
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:36 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:35 +0200

metag: Adjust system_state check

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in stop_this_cpu() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184735.283420315@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/metag/kernel/smp.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/metag/kernel/smp.c b/arch/metag/kernel/smp.c
index 232a12b..2dbbb7c 100644
--- a/arch/metag/kernel/smp.c
+++ b/arch/metag/kernel/smp.c
@@ -567,8 +567,7 @@ static void stop_this_cpu(void *data)
 {
 	unsigned int cpu = smp_processor_id();
 
-	if (system_state == SYSTEM_BOOTING ||
-	    system_state == SYSTEM_RUNNING) {
+	if (system_state <= SYSTEM_RUNNING) {
 		spin_lock(&stop_lock);
 		pr_crit("CPU%u: stopping\n", cpu);
 		dump_stack();

[tip:sched/core] powerpc: Adjust system_state check

[tip-bot for Thomas Gleixner]

Commit-ID:  a8fcfc1917681ba1ccc23a429543a67aad8bfd00
Gitweb:     http://git.kernel.org/tip/a8fcfc1917681ba1ccc23a429543a67aad8bfd00
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:37 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:35 +0200

powerpc: Adjust system_state check

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in smp_generic_cpu_bootable() to handle the
extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170516184735.359536998@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/powerpc/kernel/smp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index df2a416..1069f74 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -97,7 +97,7 @@ int smp_generic_cpu_bootable(unsigned int nr)
 	/* Special case - we inhibit secondary thread startup
 	 * during boot if the user requests it.
 	 */
-	if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
+	if (system_state < SYSTEM_RUNNING && cpu_has_feature(CPU_FTR_SMT)) {
 		if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
 			return 0;
 		if (smt_enabled_at_boot

[tip:sched/core] ACPI: Adjust system_state check

[tip-bot for Thomas Gleixner]

Commit-ID:  9762b33dc31c67e34b36ba4e787e64084b3136ff
Gitweb:     http://git.kernel.org/tip/9762b33dc31c67e34b36ba4e787e64084b3136ff
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:38 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:36 +0200

ACPI: Adjust system_state check

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Make the decision whether a pci root is hotplugged depend on SYSTEM_RUNNING
instead of !SYSTEM_BOOTING. It makes no sense to cover states greater than
SYSTEM_RUNNING as there are not hotplug events on reboot and poweroff.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/20170516184735.446455652@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/acpi/pci_root.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 919be0a..2405442 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -523,7 +523,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
 	struct acpi_pci_root *root;
 	acpi_handle handle = device->handle;
 	int no_aspm = 0;
-	bool hotadd = system_state != SYSTEM_BOOTING;
+	bool hotadd = system_state == SYSTEM_RUNNING;
 
 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 	if (!root)

[tip:sched/core] mm: Adjust system_state check

[tip-bot for Thomas Gleixner]

Commit-ID:  8cdde385c7a33afbe13fd71351da0968540fa566
Gitweb:     http://git.kernel.org/tip/8cdde385c7a33afbe13fd71351da0968540fa566
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:39 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:36 +0200

mm: Adjust system_state check

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

get_nid_for_pfn() checks for system_state == BOOTING to decide whether to
use early_pfn_to_nid() when CONFIG_DEFERRED_STRUCT_PAGE_INIT=y.

That check is dubious, because the switch to state RUNNING happes way after
page_alloc_init_late() has been invoked.

Change the check to less than RUNNING state so it covers the new
intermediate states as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184735.528279534@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/base/node.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 5548f96..0440d95 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -377,7 +377,7 @@ static int __ref get_nid_for_pfn(unsigned long pfn)
 	if (!pfn_valid_within(pfn))
 		return -1;
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
-	if (system_state == SYSTEM_BOOTING)
+	if (system_state < SYSTEM_RUNNING)
 		return early_pfn_to_nid(pfn);
 #endif
 	page = pfn_to_page(pfn);

[tip:sched/core] cpufreq/pasemi: Adjust system_state check

[tip-bot for Thomas Gleixner]

Commit-ID:  d04e31a23c3c828456cb5613f391ce4ac4e5765f
Gitweb:     http://git.kernel.org/tip/d04e31a23c3c828456cb5613f391ce4ac4e5765f
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:40 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:36 +0200

cpufreq/pasemi: Adjust system_state check

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in pas_cpufreq_cpu_exit() to handle the extra
states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170516184735.620023128@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/cpufreq/pasemi-cpufreq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cpufreq/pasemi-cpufreq.c b/drivers/cpufreq/pasemi-cpufreq.c
index 35dd4d7..b257fc7 100644
--- a/drivers/cpufreq/pasemi-cpufreq.c
+++ b/drivers/cpufreq/pasemi-cpufreq.c
@@ -226,7 +226,7 @@ static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 	 * We don't support CPU hotplug. Don't unmap after the system
 	 * has already made it to a running state.
 	 */
-	if (system_state != SYSTEM_BOOTING)
+	if (system_state >= SYSTEM_RUNNING)
 		return 0;
 
 	if (sdcasr_mapbase)

[tip:sched/core] iommu/vt-d: Adjust system_state checks

[tip-bot for Thomas Gleixner]

Commit-ID:  b608fe356fe8328665445a26ec75dfac918c8c5d
Gitweb:     http://git.kernel.org/tip/b608fe356fe8328665445a26ec75dfac918c8c5d
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:41 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:36 +0200

iommu/vt-d: Adjust system_state checks

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state checks in dmar_parse_one_atsr() and
dmar_iommu_notify_scope_dev() to handle the extra states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Joerg Roedel <joro@8bytes.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20170516184735.712365947@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/iommu/intel-iommu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index fc2765c..8500ded 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4315,7 +4315,7 @@ int dmar_parse_one_atsr(struct acpi_dmar_header *hdr, void *arg)
 	struct acpi_dmar_atsr *atsr;
 	struct dmar_atsr_unit *atsru;
 
-	if (system_state != SYSTEM_BOOTING && !intel_iommu_enabled)
+	if (system_state >= SYSTEM_RUNNING && !intel_iommu_enabled)
 		return 0;
 
 	atsr = container_of(hdr, struct acpi_dmar_atsr, header);
@@ -4565,7 +4565,7 @@ int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info)
 	struct acpi_dmar_atsr *atsr;
 	struct acpi_dmar_reserved_memory *rmrr;
 
-	if (!intel_iommu_enabled && system_state != SYSTEM_BOOTING)
+	if (!intel_iommu_enabled && system_state >= SYSTEM_RUNNING)
 		return 0;
 
 	list_for_each_entry(rmrru, &dmar_rmrr_units, list) {

[tip:sched/core] iommu/of: Adjust system_state check

[tip-bot for Thomas Gleixner]

Commit-ID:  b903dfb277c09e53d499480e9670557dcce36fbd
Gitweb:     http://git.kernel.org/tip/b903dfb277c09e53d499480e9670557dcce36fbd
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:42 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:37 +0200

iommu/of: Adjust system_state check

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in of_iommu_driver_present() to handle the
extra states.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20170516184735.788023442@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/iommu/of_iommu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 9f44ee8..b8dcf44 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -103,7 +103,7 @@ static bool of_iommu_driver_present(struct device_node *np)
 	 * it never will be. We don't want to defer indefinitely, nor attempt
 	 * to dereference __iommu_of_table after it's been freed.
 	 */
-	if (system_state > SYSTEM_BOOTING)
+	if (system_state >= SYSTEM_RUNNING)
 		return false;
 
 	return of_match_node(&__iommu_of_table, np);

[tip:sched/core] async: Adjust system_state checks

[tip-bot for Thomas Gleixner]

Commit-ID:  b4def42724594cd399cfee365221f5b38639711d
Gitweb:     http://git.kernel.org/tip/b4def42724594cd399cfee365221f5b38639711d
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:43 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:37 +0200

async: Adjust system_state checks

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in async_run_entry_fn() and
async_synchronize_cookie_domain() to handle the extra states.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184735.865155020@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/async.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/async.c b/kernel/async.c
index d2edd6e..2cbd3dd 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -114,14 +114,14 @@ static void async_run_entry_fn(struct work_struct *work)
 	ktime_t uninitialized_var(calltime), delta, rettime;
 
 	/* 1) run (and print duration) */
-	if (initcall_debug && system_state == SYSTEM_BOOTING) {
+	if (initcall_debug && system_state < SYSTEM_RUNNING) {
 		pr_debug("calling  %lli_%pF @ %i\n",
 			(long long)entry->cookie,
 			entry->func, task_pid_nr(current));
 		calltime = ktime_get();
 	}
 	entry->func(entry->data, entry->cookie);
-	if (initcall_debug && system_state == SYSTEM_BOOTING) {
+	if (initcall_debug && system_state < SYSTEM_RUNNING) {
 		rettime = ktime_get();
 		delta = ktime_sub(rettime, calltime);
 		pr_debug("initcall %lli_%pF returned 0 after %lld usecs\n",
@@ -284,14 +284,14 @@ void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain
 {
 	ktime_t uninitialized_var(starttime), delta, endtime;
 
-	if (initcall_debug && system_state == SYSTEM_BOOTING) {
+	if (initcall_debug && system_state < SYSTEM_RUNNING) {
 		pr_debug("async_waiting @ %i\n", task_pid_nr(current));
 		starttime = ktime_get();
 	}
 
 	wait_event(async_done, lowest_in_progress(domain) >= cookie);
 
-	if (initcall_debug && system_state == SYSTEM_BOOTING) {
+	if (initcall_debug && system_state < SYSTEM_RUNNING) {
 		endtime = ktime_get();
 		delta = ktime_sub(endtime, starttime);
 

[tip:sched/core] extable: Adjust system_state checks

[tip-bot for Thomas Gleixner]

Commit-ID:  0594729c24d846889408a07057b5cc9e8d931419
Gitweb:     http://git.kernel.org/tip/0594729c24d846889408a07057b5cc9e8d931419
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:44 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:37 +0200

extable: Adjust system_state checks

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in core_kernel_text() to handle the extra
states, i.e. to cover init text up to the point where the system switches
to state RUNNING.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170516184735.949992741@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/extable.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/extable.c b/kernel/extable.c
index 2676d7f..0fbdd85 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -75,7 +75,7 @@ int core_kernel_text(unsigned long addr)
 	    addr < (unsigned long)_etext)
 		return 1;
 
-	if (system_state == SYSTEM_BOOTING &&
+	if (system_state < SYSTEM_RUNNING &&
 	    init_kernel_text(addr))
 		return 1;
 	return 0;

[tip:sched/core] printk: Adjust system_state checks

[tip-bot for Thomas Gleixner]

Commit-ID:  ff48cd26fc4889b9deb5f9333d3c61746e450b7f
Gitweb:     http://git.kernel.org/tip/ff48cd26fc4889b9deb5f9333d3c61746e450b7f
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:45 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:37 +0200

printk: Adjust system_state checks

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in boot_delay_msec() to handle the extra
states.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170516184736.027534895@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/printk/printk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index a1aecf4..32fac39 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1176,7 +1176,7 @@ static void boot_delay_msec(int level)
 	unsigned long long k;
 	unsigned long timeout;
 
-	if ((boot_delay == 0 || system_state != SYSTEM_BOOTING)
+	if ((boot_delay == 0 || system_state >= SYSTEM_RUNNING)
 		|| suppress_message_printing(level)) {
 		return;
 	}

[tip:sched/core] mm/vmscan: Adjust system_state checks

[tip-bot for Thomas Gleixner]

Commit-ID:  c6202adf3a0969514299cf10ff07376a84ad09bb
Gitweb:     http://git.kernel.org/tip/c6202adf3a0969514299cf10ff07376a84ad09bb
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:46 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:37 +0200

mm/vmscan: Adjust system_state checks

To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

Adjust the system_state check in kswapd_run() to handle the extra states.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170516184736.119158930@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 8ad39bb..c3c1c6a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3652,7 +3652,7 @@ int kswapd_run(int nid)
 	pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);
 	if (IS_ERR(pgdat->kswapd)) {
 		/* failure at boot is fatal */
-		BUG_ON(system_state == SYSTEM_BOOTING);
+		BUG_ON(system_state < SYSTEM_RUNNING);
 		pr_err("Failed to start kswapd on node %d\n", nid);
 		ret = PTR_ERR(pgdat->kswapd);
 		pgdat->kswapd = NULL;

[tip:sched/core] init: Introduce SYSTEM_SCHEDULING state

[tip-bot for Thomas Gleixner]

Commit-ID:  69a78ff226fe0241ab6cb9dd961667be477e3cf7
Gitweb:     http://git.kernel.org/tip/69a78ff226fe0241ab6cb9dd961667be477e3cf7
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:47 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:38 +0200

init: Introduce SYSTEM_SCHEDULING state

might_sleep() debugging and smp_processor_id() debugging should be active
right after the scheduler starts working. The init task can invoke
smp_processor_id() from preemptible context as it is pinned on the boot cpu
until sched_smp_init() removes the pinning and lets it schedule on all non
isolated cpus.

Add a new state which allows to enable those checks earlier and add it to
the xen do_poweroff() function.

No functional change.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184736.196214622@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/xen/manage.c   | 1 +
 include/linux/kernel.h | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index c1ec8ee..9e35032 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -190,6 +190,7 @@ static void do_poweroff(void)
 {
 	switch (system_state) {
 	case SYSTEM_BOOTING:
+	case SYSTEM_SCHEDULING:
 		orderly_poweroff(true);
 		break;
 	case SYSTEM_RUNNING:
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 13bc08a..1c91f26 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -490,9 +490,13 @@ extern int root_mountflags;
 
 extern bool early_boot_irqs_disabled;
 
-/* Values used for system_state */
+/*
+ * Values used for system_state. Ordering of the states must not be changed
+ * as code checks for <, <=, >, >= STATE.
+ */
 extern enum system_states {
 	SYSTEM_BOOTING,
+	SYSTEM_SCHEDULING,
 	SYSTEM_RUNNING,
 	SYSTEM_HALT,
 	SYSTEM_POWER_OFF,

[tip:sched/core] sched/core: Enable might_sleep() and smp_processor_id() checks early

[tip-bot for Thomas Gleixner]

Commit-ID:  1c3c5eab171590f86edd8d31389d61dd1efe3037
Gitweb:     http://git.kernel.org/tip/1c3c5eab171590f86edd8d31389d61dd1efe3037
Author:     Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 16 May 2017 20:42:48 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 23 May 2017 10:01:38 +0200

sched/core: Enable might_sleep() and smp_processor_id() checks early

might_sleep() and smp_processor_id() checks are enabled after the boot
process is done. That hides bugs in the SMP bringup and driver
initialization code.

Enable it right when the scheduler starts working, i.e. when init task and
kthreadd have been created and right before the idle task enables
preemption.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184736.272225698@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 init/main.c            | 10 ++++++++++
 kernel/sched/core.c    |  4 +++-
 lib/smp_processor_id.c |  2 +-
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/init/main.c b/init/main.c
index badae3b..df58a41 100644
--- a/init/main.c
+++ b/init/main.c
@@ -414,6 +414,16 @@ static noinline void __ref rest_init(void)
 	rcu_read_lock();
 	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
 	rcu_read_unlock();
+
+	/*
+	 * Enable might_sleep() and smp_processor_id() checks.
+	 * They cannot be enabled earlier because with CONFIG_PRREMPT=y
+	 * kernel_thread() would trigger might_sleep() splats. With
+	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
+	 * already, but it's stuck on the kthreadd_done completion.
+	 */
+	system_state = SYSTEM_SCHEDULING;
+
 	complete(&kthreadd_done);
 
 	/*
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 877241e..c3e50ca 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6238,8 +6238,10 @@ void ___might_sleep(const char *file, int line, int preempt_offset)
 
 	if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
 	     !is_idle_task(current)) ||
-	    system_state != SYSTEM_RUNNING || oops_in_progress)
+	    system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING ||
+	    oops_in_progress)
 		return;
+
 	if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
 		return;
 	prev_jiffy = jiffies;
diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index 690d75b..2fb007b 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -28,7 +28,7 @@ notrace static unsigned int check_preemption_disabled(const char *what1,
 	/*
 	 * It is valid to assume CPU-locality during early bootup:
 	 */
-	if (system_state != SYSTEM_RUNNING)
+	if (system_state < SYSTEM_SCHEDULING)
 		goto out;
 
 	/*