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-rw-r--r--Documentation/cputopology.txt23
-rw-r--r--Documentation/kernel-parameters.txt4
-rw-r--r--arch/ia64/include/asm/system.h4
-rw-r--r--arch/powerpc/include/asm/system.h4
-rw-r--r--arch/s390/Kconfig7
-rw-r--r--arch/s390/include/asm/system.h1
-rw-r--r--arch/s390/include/asm/topology.h27
-rw-r--r--arch/s390/kernel/topology.c150
-rw-r--r--arch/x86/Kconfig11
-rw-r--r--arch/x86/kernel/tsc.c8
-rw-r--r--drivers/base/topology.c16
-rw-r--r--include/linux/hardirq.h9
-rw-r--r--include/linux/sched.h23
-rw-r--r--include/linux/topology.h6
-rw-r--r--include/trace/events/sched.h29
-rw-r--r--kernel/sched.c291
-rw-r--r--kernel/sched_fair.c76
-rw-r--r--kernel/sched_features.h5
-rw-r--r--kernel/sched_rt.c40
-rw-r--r--kernel/sched_stoptask.c108
-rw-r--r--kernel/softirq.c64
-rw-r--r--kernel/stop_machine.c8
-rw-r--r--net/sched/cls_cgroup.c2
23 files changed, 732 insertions, 184 deletions
diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt
index f1c5c4bccd3e..902d3151f527 100644
--- a/Documentation/cputopology.txt
+++ b/Documentation/cputopology.txt
@@ -14,25 +14,39 @@ to /proc/cpuinfo.
identifier (rather than the kernel's). The actual value is
architecture and platform dependent.
-3) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
+3) /sys/devices/system/cpu/cpuX/topology/book_id:
+
+ the book ID of cpuX. Typically it is the hardware platform's
+ identifier (rather than the kernel's). The actual value is
+ architecture and platform dependent.
+
+4) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
internel kernel map of cpuX's hardware threads within the same
core as cpuX
-4) /sys/devices/system/cpu/cpuX/topology/core_siblings:
+5) /sys/devices/system/cpu/cpuX/topology/core_siblings:
internal kernel map of cpuX's hardware threads within the same
physical_package_id.
+6) /sys/devices/system/cpu/cpuX/topology/book_siblings:
+
+ internal kernel map of cpuX's hardware threads within the same
+ book_id.
+
To implement it in an architecture-neutral way, a new source file,
-drivers/base/topology.c, is to export the 4 attributes.
+drivers/base/topology.c, is to export the 4 or 6 attributes. The two book
+related sysfs files will only be created if CONFIG_SCHED_BOOK is selected.
For an architecture to support this feature, it must define some of
these macros in include/asm-XXX/topology.h:
#define topology_physical_package_id(cpu)
#define topology_core_id(cpu)
+#define topology_book_id(cpu)
#define topology_thread_cpumask(cpu)
#define topology_core_cpumask(cpu)
+#define topology_book_cpumask(cpu)
The type of **_id is int.
The type of siblings is (const) struct cpumask *.
@@ -45,6 +59,9 @@ not defined by include/asm-XXX/topology.h:
3) thread_siblings: just the given CPU
4) core_siblings: just the given CPU
+For architectures that don't support books (CONFIG_SCHED_BOOK) there are no
+default definitions for topology_book_id() and topology_book_cpumask().
+
Additionally, CPU topology information is provided under
/sys/devices/system/cpu and includes these files. The internal
source for the output is in brackets ("[]").
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 8dd7248508a9..ed05a4a0d242 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2435,6 +2435,10 @@ and is between 256 and 4096 characters. It is defined in the file
disables clocksource verification at runtime.
Used to enable high-resolution timer mode on older
hardware, and in virtualized environment.
+ [x86] noirqtime: Do not use TSC to do irq accounting.
+ Used to run time disable IRQ_TIME_ACCOUNTING on any
+ platforms where RDTSC is slow and this accounting
+ can add overhead.
turbografx.map[2|3]= [HW,JOY]
TurboGraFX parallel port interface
diff --git a/arch/ia64/include/asm/system.h b/arch/ia64/include/asm/system.h
index 9f342a574ce8..dd028f2b13b3 100644
--- a/arch/ia64/include/asm/system.h
+++ b/arch/ia64/include/asm/system.h
@@ -272,10 +272,6 @@ void cpu_idle_wait(void);
void default_idle(void);
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
-extern void account_system_vtime(struct task_struct *);
-#endif
-
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/include/asm/system.h b/arch/powerpc/include/asm/system.h
index 6c294acac848..9c3d160670b4 100644
--- a/arch/powerpc/include/asm/system.h
+++ b/arch/powerpc/include/asm/system.h
@@ -542,10 +542,6 @@ extern void reloc_got2(unsigned long);
#define PTRRELOC(x) ((typeof(x)) add_reloc_offset((unsigned long)(x)))
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
-extern void account_system_vtime(struct task_struct *);
-#endif
-
extern struct dentry *powerpc_debugfs_root;
#endif /* __KERNEL__ */
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 958f0dadeadf..75976a141947 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -199,6 +199,13 @@ config HOTPLUG_CPU
can be controlled through /sys/devices/system/cpu/cpu#.
Say N if you want to disable CPU hotplug.
+config SCHED_BOOK
+ bool "Book scheduler support"
+ depends on SMP
+ help
+ Book scheduler support improves the CPU scheduler's decision making
+ when dealing with machines that have several books.
+
config MATHEMU
bool "IEEE FPU emulation"
depends on MARCH_G5
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index cef66210c846..38ddd8a9a9e8 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -97,7 +97,6 @@ static inline void restore_access_regs(unsigned int *acrs)
extern void account_vtime(struct task_struct *, struct task_struct *);
extern void account_tick_vtime(struct task_struct *);
-extern void account_system_vtime(struct task_struct *);
#ifdef CONFIG_PFAULT
extern void pfault_irq_init(void);
diff --git a/arch/s390/include/asm/topology.h b/arch/s390/include/asm/topology.h
index 831bd033ea77..051107a2c5e2 100644
--- a/arch/s390/include/asm/topology.h
+++ b/arch/s390/include/asm/topology.h
@@ -3,15 +3,32 @@
#include <linux/cpumask.h>
-#define mc_capable() (1)
-
-const struct cpumask *cpu_coregroup_mask(unsigned int cpu);
-
extern unsigned char cpu_core_id[NR_CPUS];
extern cpumask_t cpu_core_map[NR_CPUS];
+static inline const struct cpumask *cpu_coregroup_mask(unsigned int cpu)
+{
+ return &cpu_core_map[cpu];
+}
+
#define topology_core_id(cpu) (cpu_core_id[cpu])
#define topology_core_cpumask(cpu) (&cpu_core_map[cpu])
+#define mc_capable() (1)
+
+#ifdef CONFIG_SCHED_BOOK
+
+extern unsigned char cpu_book_id[NR_CPUS];
+extern cpumask_t cpu_book_map[NR_CPUS];
+
+static inline const struct cpumask *cpu_book_mask(unsigned int cpu)
+{
+ return &cpu_book_map[cpu];
+}
+
+#define topology_book_id(cpu) (cpu_book_id[cpu])
+#define topology_book_cpumask(cpu) (&cpu_book_map[cpu])
+
+#endif /* CONFIG_SCHED_BOOK */
int topology_set_cpu_management(int fc);
void topology_schedule_update(void);
@@ -30,6 +47,8 @@ static inline void s390_init_cpu_topology(void)
};
#endif
+#define SD_BOOK_INIT SD_CPU_INIT
+
#include <asm-generic/topology.h>
#endif /* _ASM_S390_TOPOLOGY_H */
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index bcef00766a64..13559c993847 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -57,8 +57,8 @@ struct tl_info {
union tl_entry tle[0];
};
-struct core_info {
- struct core_info *next;
+struct mask_info {
+ struct mask_info *next;
unsigned char id;
cpumask_t mask;
};
@@ -66,7 +66,6 @@ struct core_info {
static int topology_enabled;
static void topology_work_fn(struct work_struct *work);
static struct tl_info *tl_info;
-static struct core_info core_info;
static int machine_has_topology;
static struct timer_list topology_timer;
static void set_topology_timer(void);
@@ -74,38 +73,37 @@ static DECLARE_WORK(topology_work, topology_work_fn);
/* topology_lock protects the core linked list */
static DEFINE_SPINLOCK(topology_lock);
+static struct mask_info core_info;
cpumask_t cpu_core_map[NR_CPUS];
unsigned char cpu_core_id[NR_CPUS];
-static cpumask_t cpu_coregroup_map(unsigned int cpu)
+#ifdef CONFIG_SCHED_BOOK
+static struct mask_info book_info;
+cpumask_t cpu_book_map[NR_CPUS];
+unsigned char cpu_book_id[NR_CPUS];
+#endif
+
+static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
{
- struct core_info *core = &core_info;
- unsigned long flags;
cpumask_t mask;
cpus_clear(mask);
if (!topology_enabled || !machine_has_topology)
return cpu_possible_map;
- spin_lock_irqsave(&topology_lock, flags);
- while (core) {
- if (cpu_isset(cpu, core->mask)) {
- mask = core->mask;
+ while (info) {
+ if (cpu_isset(cpu, info->mask)) {
+ mask = info->mask;
break;
}
- core = core->next;
+ info = info->next;
}
- spin_unlock_irqrestore(&topology_lock, flags);
if (cpus_empty(mask))
mask = cpumask_of_cpu(cpu);
return mask;
}
-const struct cpumask *cpu_coregroup_mask(unsigned int cpu)
-{
- return &cpu_core_map[cpu];
-}
-
-static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
+static void add_cpus_to_mask(struct tl_cpu *tl_cpu, struct mask_info *book,
+ struct mask_info *core)
{
unsigned int cpu;
@@ -117,23 +115,35 @@ static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
for_each_present_cpu(lcpu) {
- if (cpu_logical_map(lcpu) == rcpu) {
- cpu_set(lcpu, core->mask);
- cpu_core_id[lcpu] = core->id;
- smp_cpu_polarization[lcpu] = tl_cpu->pp;
- }
+ if (cpu_logical_map(lcpu) != rcpu)
+ continue;
+#ifdef CONFIG_SCHED_BOOK
+ cpu_set(lcpu, book->mask);
+ cpu_book_id[lcpu] = book->id;
+#endif
+ cpu_set(lcpu, core->mask);
+ cpu_core_id[lcpu] = core->id;
+ smp_cpu_polarization[lcpu] = tl_cpu->pp;
}
}
}
-static void clear_cores(void)
+static void clear_masks(void)
{
- struct core_info *core = &core_info;
+ struct mask_info *info;
- while (core) {
- cpus_clear(core->mask);
- core = core->next;
+ info = &core_info;
+ while (info) {
+ cpus_clear(info->mask);
+ info = info->next;
+ }
+#ifdef CONFIG_SCHED_BOOK
+ info = &book_info;
+ while (info) {
+ cpus_clear(info->mask);
+ info = info->next;
}
+#endif
}
static union tl_entry *next_tle(union tl_entry *tle)
@@ -146,29 +156,36 @@ static union tl_entry *next_tle(union tl_entry *tle)
static void tl_to_cores(struct tl_info *info)
{
+#ifdef CONFIG_SCHED_BOOK
+ struct mask_info *book = &book_info;
+#else
+ struct mask_info *book = NULL;
+#endif
+ struct mask_info *core = &core_info;
union tl_entry *tle, *end;
- struct core_info *core = &core_info;
+
spin_lock_irq(&topology_lock);
- clear_cores();
+ clear_masks();
tle = info->tle;
end = (union tl_entry *)((unsigned long)info + info->length);
while (tle < end) {
switch (tle->nl) {
- case 5:
- case 4:
- case 3:
+#ifdef CONFIG_SCHED_BOOK
case 2:
+ book = book->next;
+ book->id = tle->container.id;
break;
+#endif
case 1:
core = core->next;
core->id = tle->container.id;
break;
case 0:
- add_cpus_to_core(&tle->cpu, core);
+ add_cpus_to_mask(&tle->cpu, book, core);
break;
default:
- clear_cores();
+ clear_masks();
machine_has_topology = 0;
goto out;
}
@@ -221,10 +238,29 @@ int topology_set_cpu_management(int fc)
static void update_cpu_core_map(void)
{
+ unsigned long flags;
int cpu;
- for_each_possible_cpu(cpu)
- cpu_core_map[cpu] = cpu_coregroup_map(cpu);
+ spin_lock_irqsave(&topology_lock, flags);
+ for_each_possible_cpu(cpu) {
+ cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
+#ifdef CONFIG_SCHED_BOOK
+ cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
+#endif
+ }
+ spin_unlock_irqrestore(&topology_lock, flags);
+}
+
+static void store_topology(struct tl_info *info)
+{
+#ifdef CONFIG_SCHED_BOOK
+ int rc;
+
+ rc = stsi(info, 15, 1, 3);
+ if (rc != -ENOSYS)
+ return;
+#endif
+ stsi(info, 15, 1, 2);
}
int arch_update_cpu_topology(void)
@@ -238,7 +274,7 @@ int arch_update_cpu_topology(void)
topology_update_polarization_simple();
return 0;
}
- stsi(info, 15, 1, 2);
+ store_topology(info);
tl_to_cores(info);
update_cpu_core_map();
for_each_online_cpu(cpu) {
@@ -299,12 +335,24 @@ out:
}
__initcall(init_topology_update);
+static void alloc_masks(struct tl_info *info, struct mask_info *mask, int offset)
+{
+ int i, nr_masks;
+
+ nr_masks = info->mag[NR_MAG - offset];
+ for (i = 0; i < info->mnest - offset; i++)
+ nr_masks *= info->mag[NR_MAG - offset - 1 - i];
+ nr_masks = max(nr_masks, 1);
+ for (i = 0; i < nr_masks; i++) {
+ mask->next = alloc_bootmem(sizeof(struct mask_info));
+ mask = mask->next;
+ }
+}
+
void __init s390_init_cpu_topology(void)
{
unsigned long long facility_bits;
struct tl_info *info;
- struct core_info *core;
- int nr_cores;
int i;
if (stfle(&facility_bits, 1) <= 0)
@@ -315,25 +363,13 @@ void __init s390_init_cpu_topology(void)
tl_info = alloc_bootmem_pages(PAGE_SIZE);
info = tl_info;
- stsi(info, 15, 1, 2);
-
- nr_cores = info->mag[NR_MAG - 2];
- for (i = 0; i < info->mnest - 2; i++)
- nr_cores *= info->mag[NR_MAG - 3 - i];
-
+ store_topology(info);
pr_info("The CPU configuration topology of the machine is:");
for (i = 0; i < NR_MAG; i++)
printk(" %d", info->mag[i]);
printk(" / %d\n", info->mnest);
-
- core = &core_info;
- for (i = 0; i < nr_cores; i++) {
- core->next = alloc_bootmem(sizeof(struct core_info));
- core = core->next;
- if (!core)
- goto error;
- }
- return;
-error:
- machine_has_topology = 0;
+ alloc_masks(info, &core_info, 2);
+#ifdef CONFIG_SCHED_BOOK
+ alloc_masks(info, &book_info, 3);
+#endif
}
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fd227d6b8d9c..89b88e3a56e9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -799,6 +799,17 @@ config SCHED_MC
making when dealing with multi-core CPU chips at a cost of slightly
increased overhead in some places. If unsure say N here.
+config IRQ_TIME_ACCOUNTING
+ bool "Fine granularity task level IRQ time accounting"
+ default n
+ ---help---
+ Select this option to enable fine granularity task irq time
+ accounting. This is done by reading a timestamp on each
+ transitions between softirq and hardirq state, so there can be a
+ small performance impact.
+
+ If in doubt, say N here.
+
source "kernel/Kconfig.preempt"
config X86_UP_APIC
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 26a863a9c2a8..a1c2cd768538 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -104,10 +104,14 @@ int __init notsc_setup(char *str)
__setup("notsc", notsc_setup);
+static int no_sched_irq_time;
+
static int __init tsc_setup(char *str)
{
if (!strcmp(str, "reliable"))
tsc_clocksource_reliable = 1;
+ if (!strncmp(str, "noirqtime", 9))
+ no_sched_irq_time = 1;
return 1;
}
@@ -801,6 +805,7 @@ void mark_tsc_unstable(char *reason)
if (!tsc_unstable) {
tsc_unstable = 1;
sched_clock_stable = 0;
+ disable_sched_clock_irqtime();
printk(KERN_INFO "Marking TSC unstable due to %s\n", reason);
/* Change only the rating, when not registered */
if (clocksource_tsc.mult)
@@ -987,6 +992,9 @@ void __init tsc_init(void)
/* now allow native_sched_clock() to use rdtsc */
tsc_disabled = 0;
+ if (!no_sched_irq_time)
+ enable_sched_clock_irqtime();
+
lpj = ((u64)tsc_khz * 1000);
do_div(lpj, HZ);
lpj_fine = lpj;
diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index 9fc630ce1ddb..f6f37a05a0c3 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -45,7 +45,8 @@ static ssize_t show_##name(struct sys_device *dev, \
return sprintf(buf, "%d\n", topology_##name(cpu)); \
}
-#if defined(topology_thread_cpumask) || defined(topology_core_cpumask)
+#if defined(topology_thread_cpumask) || defined(topology_core_cpumask) || \
+ defined(topology_book_cpumask)
static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf)
{
ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
@@ -114,6 +115,14 @@ define_siblings_show_func(core_cpumask);
define_one_ro_named(core_siblings, show_core_cpumask);
define_one_ro_named(core_siblings_list, show_core_cpumask_list);
+#ifdef CONFIG_SCHED_BOOK
+define_id_show_func(book_id);
+define_one_ro(book_id);
+define_siblings_show_func(book_cpumask);
+define_one_ro_named(book_siblings, show_book_cpumask);
+define_one_ro_named(book_siblings_list, show_book_cpumask_list);
+#endif
+
static struct attribute *default_attrs[] = {
&attr_physical_package_id.attr,
&attr_core_id.attr,
@@ -121,6 +130,11 @@ static struct attribute *default_attrs[] = {
&attr_thread_siblings_list.attr,
&attr_core_siblings.attr,
&attr_core_siblings_list.attr,
+#ifdef CONFIG_SCHED_BOOK
+ &attr_book_id.attr,
+ &attr_book_siblings.attr,
+ &attr_book_siblings_list.attr,
+#endif
NULL
};
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 1f4517d55b19..96c323ac44df 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -64,6 +64,8 @@
#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
#define NMI_OFFSET (1UL << NMI_SHIFT)
+#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
+
#ifndef PREEMPT_ACTIVE
#define PREEMPT_ACTIVE_BITS 1
#define PREEMPT_ACTIVE_SHIFT (NMI_SHIFT + NMI_BITS)
@@ -82,10 +84,13 @@
/*
* Are we doing bottom half or hardware interrupt processing?
* Are we in a softirq context? Interrupt context?
+ * in_softirq - Are we currently processing softirq or have bh disabled?
+ * in_serving_softirq - Are we currently processing softirq?
*/
#define in_irq() (hardirq_count())
#define in_softirq() (softirq_count())
#define in_interrupt() (irq_count())
+#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
/*
* Are we in NMI context?
@@ -132,10 +137,12 @@ extern void synchronize_irq(unsigned int irq);
struct task_struct;
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+#if !defined(CONFIG_VIRT_CPU_ACCOUNTING) && !defined(CONFIG_IRQ_TIME_ACCOUNTING)
static inline void account_system_vtime(struct task_struct *tsk)
{
}
+#else
+extern void account_system_vtime(struct task_struct *tsk);
#endif
#if defined(CONFIG_NO_HZ)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 61b4ecf1da50..0383601a927c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -875,6 +875,7 @@ enum sched_domain_level {
SD_LV_NONE = 0,
SD_LV_SIBLING,
SD_LV_MC,
+ SD_LV_BOOK,
SD_LV_CPU,
SD_LV_NODE,
SD_LV_ALLNODES,
@@ -1690,8 +1691,7 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *
/*
* Per process flags
*/
-#define PF_ALIGNWARN 0x00000001 /* Print alignment warning msgs */
- /* Not implemented yet, only for 486*/
+#define PF_KSOFTIRQD 0x00000001 /* I am ksoftirqd */
#define PF_STARTING 0x00000002 /* being created */
#define PF_EXITING 0x00000004 /* getting shut down */
#define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */
@@ -1837,6 +1837,19 @@ extern void sched_clock_idle_sleep_event(void);
extern void sched_clock_idle_wakeup_event(u64 delta_ns);
#endif
+#ifdef CONFIG_IRQ_TIME_ACCOUNTING
+/*
+ * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
+ * The reason for this explicit opt-in is not to have perf penalty with
+ * slow sched_clocks.
+ */
+extern void enable_sched_clock_irqtime(void);
+extern void disable_sched_clock_irqtime(void);
+#else
+static inline void enable_sched_clock_irqtime(void) {}
+static inline void disable_sched_clock_irqtime(void) {}
+#endif
+
extern unsigned long long
task_sched_runtime(struct task_struct *task);
extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
@@ -2378,9 +2391,9 @@ extern int __cond_resched_lock(spinlock_t *lock);
extern int __cond_resched_softirq(void);
-#define cond_resched_softirq() ({ \
- __might_sleep(__FILE__, __LINE__, SOFTIRQ_OFFSET); \
- __cond_resched_softirq(); \
+#define cond_resched_softirq() ({ \
+ __might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
+ __cond_resched_softirq(); \
})
/*
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 64e084ff5e5c..b91a40e847d2 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -201,6 +201,12 @@ int arch_update_cpu_topology(void);
.balance_interval = 64, \
}
+#ifdef CONFIG_SCHED_BOOK
+#ifndef SD_BOOK_INIT
+#error Please define an appropriate SD_BOOK_INIT in include/asm/topology.h!!!
+#endif
+#endif /* CONFIG_SCHED_BOOK */
+
#ifdef CONFIG_NUMA
#ifndef SD_NODE_INIT
#error Please define an appropriate SD_NODE_INIT in include/asm/topology.h!!!
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 9208c92aeab5..f6334782a593 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -362,6 +362,35 @@ TRACE_EVENT(sched_stat_runtime,
(unsigned long long)__entry->vruntime)
);
+/*
+ * Tracepoint for showing priority inheritance modifying a tasks
+ * priority.
+ */
+TRACE_EVENT(sched_pi_setprio,
+
+ TP_PROTO(struct task_struct *tsk, int newprio),
+
+ TP_ARGS(tsk, newprio),
+
+ TP_STRUCT__entry(
+ __array( char, comm, TASK_COMM_LEN )
+ __field( pid_t, pid )
+ __field( int, oldprio )
+ __field( int, newprio )
+ ),
+
+ TP_fast_assign(
+ memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
+ __entry->pid = tsk->pid;
+ __entry->oldprio = tsk->prio;
+ __entry->newprio = newprio;
+ ),
+
+ TP_printk("comm=%s pid=%d oldprio=%d newprio=%d",
+ __entry->comm, __entry->pid,
+ __entry->oldprio, __entry->newprio)
+);
+
#endif /* _TRACE_SCHED_H */
/* This part must be outside protection */
diff --git a/kernel/sched.c b/kernel/sched.c
index 5a5cc33e4999..d42992bccdfa 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -426,9 +426,7 @@ struct root_domain {
*/
cpumask_var_t rto_mask;
atomic_t rto_count;
-#ifdef CONFIG_SMP
struct cpupri cpupri;
-#endif
};
/*
@@ -437,7 +435,7 @@ struct root_domain {
*/
static struct root_domain def_root_domain;
-#endif
+#endif /* CONFIG_SMP */
/*
* This is the main, per-CPU runqueue data structure.
@@ -488,11 +486,12 @@ struct rq {
*/
unsigned long nr_uninterruptible;
- struct task_struct *curr, *idle;
+ struct task_struct *curr, *idle, *stop;
unsigned long next_balance;
struct mm_struct *prev_mm;
u64 clock;
+ u64 clock_task;
atomic_t nr_iowait;
@@ -520,6 +519,10 @@ struct rq {
u64 avg_idle;
#endif
+#ifdef CONFIG_IRQ_TIME_ACCOUNTING
+ u64 prev_irq_time;
+#endif
+
/* calc_load related fields */
unsigned long calc_load_update;
long calc_load_active;
@@ -643,10 +646,22 @@ static inline struct task_group *task_group(struct task_struct *p)
#endif /* CONFIG_CGROUP_SCHED */
+static u64 irq_time_cpu(int cpu);
+static void sched_irq_time_avg_update(struct rq *rq, u64 irq_time);
+
inline void update_rq_clock(struct rq *rq)
{
- if (!rq->skip_clock_update)
- rq->clock = sched_clock_cpu(cpu_of(rq));
+ if (!rq->skip_clock_update) {
+ int cpu = cpu_of(rq);
+ u64 irq_time;
+
+ rq->clock = sched_clock_cpu(cpu);
+ irq_time = irq_time_cpu(cpu);
+ if (rq->clock - irq_time > rq->clock_task)
+ rq->clock_task = rq->clock - irq_time;
+
+ sched_irq_time_avg_update(rq, irq_time);
+ }
}
/*
@@ -723,7 +738,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[64];
- char *cmp = buf;
+ char *cmp;
int neg = 0;
int i;
@@ -734,6 +749,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
return -EFAULT;
buf[cnt] = 0;
+ cmp = strstrip(buf);
if (strncmp(buf, "NO_", 3) == 0) {
neg = 1;
@@ -741,9 +757,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
}
for (i = 0; sched_feat_names[i]; i++) {
- int len = strlen(sched_feat_names[i]);
-
- if (strncmp(cmp, sched_feat_names[i], len) == 0) {
+ if (strcmp(cmp, sched_feat_names[i]) == 0) {
if (neg)
sysctl_sched_features &= ~(1UL << i);
else
@@ -1840,7 +1854,7 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
static const struct sched_class rt_sched_class;
-#define sched_class_highest (&rt_sched_class)
+#define sched_class_highest (&stop_sched_class)
#define for_each_class(class) \
for (class = sched_class_highest; class; class = class->next)
@@ -1858,12 +1872,6 @@ static void dec_nr_running(struct rq *rq)
static void set_load_weight(struct task_struct *p)
{
- if (task_has_rt_policy(p)) {
- p->se.load.weight = 0;
- p->se.load.inv_weight = WMULT_CONST;
- return;
- }
-
/*
* SCHED_IDLE tasks get minimal weight:
*/
@@ -1917,13 +1925,132 @@ static void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
dec_nr_running(rq);
}
+#ifdef CONFIG_IRQ_TIME_ACCOUNTING
+
+/*
+ * There are no locks covering percpu hardirq/softirq time.
+ * They are only modified in account_system_vtime, on corresponding CPU
+ * with interrupts disabled. So, writes are safe.
+ * They are read and saved off onto struct rq in update_rq_clock().
+ * This may result in other CPU reading this CPU's irq time and can
+ * race with irq/account_system_vtime on this CPU. We would either get old
+ * or new value (or semi updated value on 32 bit) with a side effect of
+ * accounting a slice of irq time to wrong task when irq is in progress
+ * while we read rq->clock. That is a worthy compromise in place of having
+ * locks on each irq in account_system_time.
+ */
+static DEFINE_PER_CPU(u64, cpu_hardirq_time);
+static DEFINE_PER_CPU(u64, cpu_softirq_time);
+
+static DEFINE_PER_CPU(u64, irq_start_time);
+static int sched_clock_irqtime;
+
+void enable_sched_clock_irqtime(void)
+{
+ sched_clock_irqtime = 1;
+}
+
+void disable_sched_clock_irqtime(void)
+{
+ sched_clock_irqtime = 0;
+}
+
+static u64 irq_time_cpu(int cpu)
+{
+ if (!sched_clock_irqtime)
+ return 0;
+
+ return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
+}
+
+void account_system_vtime(struct task_struct *curr)
+{
+ unsigned long flags;
+ int cpu;
+ u64 now, delta;
+
+ if (!sched_clock_irqtime)
+ return;
+
+ local_irq_save(flags);
+
+ cpu = smp_processor_id();
+ now = sched_clock_cpu(cpu);
+ delta = now - per_cpu(irq_start_time, cpu);
+ per_cpu(irq_start_time, cpu) = now;
+ /*
+ * We do not account for softirq time from ksoftirqd here.
+ * We want to continue accounting softirq time to ksoftirqd thread
+ * in that case, so as not to confuse scheduler with a special task
+ * that do not consume any time, but still wants to run.
+ */
+ if (hardirq_count())
+ per_cpu(cpu_hardirq_time, cpu) += delta;
+ else if (in_serving_softirq() && !(curr->flags & PF_KSOFTIRQD))
+ per_cpu(cpu_softirq_time, cpu) += delta;
+
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(account_system_vtime);
+
+static void sched_irq_time_avg_update(struct rq *rq, u64 curr_irq_time)
+{
+ if (sched_clock_irqtime && sched_feat(NONIRQ_POWER)) {
+ u64 delta_irq = curr_irq_time - rq->prev_irq_time;
+ rq->prev_irq_time = curr_irq_time;
+ sched_rt_avg_update(rq, delta_irq);
+ }
+}
+
+#else
+
+static u64 irq_time_cpu(int cpu)
+{
+ return 0;
+}
+
+static void sched_irq_time_avg_update(struct rq *rq, u64 curr_irq_time) { }
+
+#endif
+
#include "sched_idletask.c"
#include "sched_fair.c"
#include "sched_rt.c"
+#include "sched_stoptask.c"
#ifdef CONFIG_SCHED_DEBUG
# include "sched_debug.c"
#endif
+void sched_set_stop_task(int cpu, struct task_struct *stop)
+{
+ struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
+ struct task_struct *old_stop = cpu_rq(cpu)->stop;
+
+ if (stop) {
+ /*
+ * Make it appear like a SCHED_FIFO task, its something
+ * userspace knows about and won't get confused about.
+ *
+ * Also, it will make PI more or less work without too
+ * much confusion -- but then, stop work should not
+ * rely on PI working anyway.
+ */
+ sched_setscheduler_nocheck(stop, SCHED_FIFO, &param);
+
+ stop->sched_class = &stop_sched_class;
+ }
+
+ cpu_rq(cpu)->stop = stop;
+
+ if (old_stop) {
+ /*
+ * Reset it back to a normal scheduling class so that
+ * it can die in pieces.
+ */
+ old_stop->sched_class = &rt_sched_class;
+ }
+}
+
/*
* __normal_prio - return the priority that is based on the static prio
*/
@@ -2003,6 +2130,9 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
if (p->sched_class != &fair_sched_class)
return 0;
+ if (unlikely(p->policy == SCHED_IDLE))
+ return 0;
+
/*
* Buddy candidates are cache hot:
*/
@@ -2852,14 +2982,14 @@ context_switch(struct rq *rq, struct task_struct *prev,
*/
arch_start_context_switch(prev);
- if (likely(!mm)) {
+ if (!mm) {
next->active_mm = oldmm;
atomic_inc(&oldmm->mm_count);
enter_lazy_tlb(oldmm, next);
} else
switch_mm(oldmm, mm, next);
- if (likely(!prev->mm)) {
+ if (!prev->mm) {
prev->active_mm = NULL;
rq->prev_mm = oldmm;
}
@@ -3248,7 +3378,7 @@ static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
if (task_current(rq, p)) {
update_rq_clock(rq);
- ns = rq->clock - p->se.exec_start;
+ ns = rq->clock_task - p->se.exec_start;
if ((s64)ns < 0)
ns = 0;
}
@@ -3397,7 +3527,7 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
tmp = cputime_to_cputime64(cputime);
if (hardirq_count() - hardirq_offset)
cpustat->irq = cputime64_add(cpustat->irq, tmp);
- else if (softirq_count())
+ else if (in_serving_softirq())
cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
else
cpustat->system = cputime64_add(cpustat->system, tmp);
@@ -3723,17 +3853,13 @@ pick_next_task(struct rq *rq)
return p;
}
- class = sched_class_highest;
- for ( ; ; ) {
+ for_each_class(class) {
p = class->pick_next_task(rq);
if (p)
return p;
- /*
- * Will never be NULL as the idle class always
- * returns a non-NULL p:
- */
- class = class->next;
}
+
+ BUG(); /* the idle class will always have a runnable task */
}
/*
@@ -4358,6 +4484,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
rq = task_rq_lock(p, &flags);
+ trace_sched_pi_setprio(p, prio);
oldprio = p->prio;
prev_class = p->sched_class;
on_rq = p->se.on_rq;
@@ -4661,6 +4788,15 @@ recheck:
*/
rq = __task_rq_lock(p);
+ /*
+ * Changing the policy of the stop threads its a very bad idea
+ */
+ if (p == rq->stop) {
+ __task_rq_unlock(rq);
+ raw_spin_unlock_irqrestore(&p->pi_lock, flags);
+ return -EINVAL;
+ }
+
#ifdef CONFIG_RT_GROUP_SCHED
if (user) {
/*
@@ -4893,7 +5029,7 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
cpuset_cpus_allowed(p, cpus_allowed);
cpumask_and(new_mask, in_mask, cpus_allowed);
- again:
+again:
retval = set_cpus_allowed_ptr(p, new_mask);
if (!retval) {
@@ -6526,6 +6662,7 @@ struct s_data {
cpumask_var_t nodemask;
cpumask_var_t this_sibling_map;
cpumask_var_t this_core_map;
+ cpumask_var_t this_book_map;
cpumask_var_t send_covered;
cpumask_var_t tmpmask;
struct sched_group **sched_group_nodes;
@@ -6537,6 +6674,7 @@ enum s_alloc {
sa_rootdomain,
sa_tmpmask,
sa_send_covered,
+ sa_this_book_map,
sa_this_core_map,
sa_this_sibling_map,
sa_nodemask,
@@ -6572,31 +6710,48 @@ cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map,
#ifdef CONFIG_SCHED_MC
static DEFINE_PER_CPU(struct static_sched_domain, core_domains);
static DEFINE_PER_CPU(struct static_sched_group, sched_group_core);
-#endif /* CONFIG_SCHED_MC */
-#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
static int
cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
struct sched_group **sg, struct cpumask *mask)
{
int group;
-
+#ifdef CONFIG_SCHED_SMT
cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
group = cpumask_first(mask);
+#else
+ group = cpu;
+#endif
if (sg)
*sg = &per_cpu(sched_group_core, group).sg;
return group;
}
-#elif defined(CONFIG_SCHED_MC)
+#endif /* CONFIG_SCHED_MC */
+
+/*
+ * book sched-domains:
+ */
+#ifdef CONFIG_SCHED_BOOK
+static DEFINE_PER_CPU(struct static_sched_domain, book_domains);
+static DEFINE_PER_CPU(struct static_sched_group, sched_group_book);
+
static int
-cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
- struct sched_group **sg, struct cpumask *unused)
+cpu_to_book_group(int cpu, const struct cpumask *cpu_map,
+ struct sched_group **sg, struct cpumask *mask)
{
+ int group = cpu;
+#ifdef CONFIG_SCHED_MC
+ cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map);
+ group = cpumask_first(mask);
+#elif defined(CONFIG_SCHED_SMT)
+ cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
+ group = cpumask_first(mask);
+#endif
if (sg)
- *sg = &per_cpu(sched_group_core, cpu).sg;
- return cpu;
+ *sg = &per_cpu(sched_group_book, group).sg;
+ return group;
}
-#endif
+#endif /* CONFIG_SCHED_BOOK */
static DEFINE_PER_CPU(struct static_sched_domain, phys_domains);
static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys);
@@ -6606,7 +6761,10 @@ cpu_to_phys_group(int cpu, const struct cpumask *cpu_map,
struct sched_group **sg, struct cpumask *mask)
{
int group;
-#ifdef CONFIG_SCHED_MC
+#ifdef CONFIG_SCHED_BOOK
+ cpumask_and(mask, cpu_book_mask(cpu), cpu_map);
+ group = cpumask_first(mask);
+#elif defined(CONFIG_SCHED_MC)
cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map);
group = cpumask_first(mask);
#elif defined(CONFIG_SCHED_SMT)
@@ -6867,6 +7025,9 @@ SD_INIT_FUNC(CPU)
#ifdef CONFIG_SCHED_MC
SD_INIT_FUNC(MC)
#endif
+#ifdef CONFIG_SCHED_BOOK
+ SD_INIT_FUNC(BOOK)
+#endif
static int default_relax_domain_level = -1;
@@ -6916,6 +7077,8 @@ static void __free_domain_allocs(struct s_data *d, enum s_alloc what,
free_cpumask_var(d->tmpmask); /* fall through */
case sa_send_covered:
free_cpumask_var(d->send_covered); /* fall through */
+ case sa_this_book_map:
+ free_cpumask_var(d->this_book_map); /* fall through */
case sa_this_core_map:
free_cpumask_var(d->this_core_map); /* fall through */
case sa_this_sibling_map:
@@ -6962,8 +7125,10 @@ static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
return sa_nodemask;
if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL))
return sa_this_sibling_map;
- if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL))
+ if (!alloc_cpumask_var(&d->this_book_map, GFP_KERNEL))
return sa_this_core_map;
+ if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL))
+ return sa_this_book_map;
if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL))
return sa_send_covered;
d->rd = alloc_rootdomain();
@@ -7021,6 +7186,23 @@ static struct sched_domain *__build_cpu_sched_domain(struct s_data *d,
return sd;
}
+static struct sched_domain *__build_book_sched_domain(struct s_data *d,
+ const struct cpumask *cpu_map, struct sched_domain_attr *attr,
+ struct sched_domain *parent, int i)
+{
+ struct sched_domain *sd = parent;
+#ifdef CONFIG_SCHED_BOOK
+ sd = &per_cpu(book_domains, i).sd;
+ SD_INIT(sd, BOOK);
+ set_domain_attribute(sd, attr);
+ cpumask_and(sched_domain_span(sd), cpu_map, cpu_book_mask(i));
+ sd->parent = parent;
+ parent->child = sd;
+ cpu_to_book_group(i, cpu_map, &sd->groups, d->tmpmask);
+#endif
+ return sd;
+}
+
static struct sched_domain *__build_mc_sched_domain(struct s_data *d,
const struct cpumask *cpu_map, struct sched_domain_attr *attr,
struct sched_domain *parent, int i)
@@ -7078,6 +7260,15 @@ static void build_sched_groups(struct s_data *d, enum sched_domain_level l,
d->send_covered, d->tmpmask);
break;
#endif
+#ifdef CONFIG_SCHED_BOOK
+ case SD_LV_BOOK: /* set up book groups */
+ cpumask_and(d->this_book_map, cpu_map, cpu_book_mask(cpu));
+ if (cpu == cpumask_first(d->this_book_map))
+ init_sched_build_groups(d->this_book_map, cpu_map,
+ &cpu_to_book_group,
+ d->send_covered, d->tmpmask);
+ break;
+#endif
case SD_LV_CPU: /* set up physical groups */
cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map);
if (!cpumask_empty(d->nodemask))
@@ -7125,12 +7316,14 @@ static int __build_sched_domains(const struct cpumask *cpu_map,
sd = __build_numa_sched_domains(&d, cpu_map, attr, i);
sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i);
+ sd = __build_book_sched_domain(&d, cpu_map, attr, sd, i);
sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i);
sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i);
}
for_each_cpu(i, cpu_map) {
build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i);
+ build_sched_groups(&d, SD_LV_BOOK, cpu_map, i);
build_sched_groups(&d, SD_LV_MC, cpu_map, i);
}
@@ -7161,6 +7354,12 @@ static int __build_sched_domains(const struct cpumask *cpu_map,
init_sched_groups_power(i, sd);
}
#endif
+#ifdef CONFIG_SCHED_BOOK
+ for_each_cpu(i, cpu_map) {
+ sd = &per_cpu(book_domains, i).sd;
+ init_sched_groups_power(i, sd);
+ }
+#endif
for_each_cpu(i, cpu_map) {
sd = &per_cpu(phys_domains, i).sd;
@@ -7186,6 +7385,8 @@ static int __build_sched_domains(const struct cpumask *cpu_map,
sd = &per_cpu(cpu_domains, i).sd;
#elif defined(CONFIG_SCHED_MC)
sd = &per_cpu(core_domains, i).sd;
+#elif defined(CONFIG_SCHED_BOOK)
+ sd = &per_cpu(book_domains, i).sd;
#else
sd = &per_cpu(phys_domains, i).sd;
#endif
@@ -8090,9 +8291,9 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
return 1;
- err_free_rq:
+err_free_rq:
kfree(cfs_rq);
- err:
+err:
return 0;
}
@@ -8180,9 +8381,9 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
return 1;
- err_free_rq:
+err_free_rq:
kfree(rt_rq);
- err:
+err:
return 0;
}
@@ -8540,7 +8741,7 @@ static int tg_set_bandwidth(struct task_group *tg,
raw_spin_unlock(&rt_rq->rt_runtime_lock);
}
raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock);
- unlock:
+unlock:
read_unlock(&tasklist_lock);
mutex_unlock(&rt_constraints_mutex);
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5f996d36ac5d..933f3d1b62ea 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -25,7 +25,7 @@
/*
* Targeted preemption latency for CPU-bound tasks:
- * (default: 5ms * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds)
*
* NOTE: this latency value is not the same as the concept of
* 'timeslice length' - timeslices in CFS are of variable length
@@ -52,7 +52,7 @@ enum sched_tunable_scaling sysctl_sched_tunable_scaling
/*
* Minimal preemption granularity for CPU-bound tasks:
- * (default: 2 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
unsigned int sysctl_sched_min_granularity = 750000ULL;
unsigned int normalized_sysctl_sched_min_granularity = 750000ULL;
@@ -519,7 +519,7 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
static void update_curr(struct cfs_rq *cfs_rq)
{
struct sched_entity *curr = cfs_rq->curr;
- u64 now = rq_of(cfs_rq)->clock;
+ u64 now = rq_of(cfs_rq)->clock_task;
unsigned long delta_exec;
if (unlikely(!curr))
@@ -602,7 +602,7 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
/*
* We are starting a new run period:
*/
- se->exec_start = rq_of(cfs_rq)->clock;
+ se->exec_start = rq_of(cfs_rq)->clock_task;
}
/**************************************************
@@ -1764,6 +1764,10 @@ static void pull_task(struct rq *src_rq, struct task_struct *p,
set_task_cpu(p, this_cpu);
activate_task(this_rq, p, 0);
check_preempt_curr(this_rq, p, 0);
+
+ /* re-arm NEWIDLE balancing when moving tasks */
+ src_rq->avg_idle = this_rq->avg_idle = 2*sysctl_sched_migration_cost;
+ this_rq->idle_stamp = 0;
}
/*
@@ -1798,7 +1802,7 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
* 2) too many balance attempts have failed.
*/
- tsk_cache_hot = task_hot(p, rq->clock, sd);
+ tsk_cache_hot = task_hot(p, rq->clock_task, sd);
if (!tsk_cache_hot ||
sd->nr_balance_failed > sd->cache_nice_tries) {
#ifdef CONFIG_SCHEDSTATS
@@ -2030,12 +2034,14 @@ struct sd_lb_stats {
unsigned long this_load;
unsigned long this_load_per_task;
unsigned long this_nr_running;
+ unsigned long this_has_capacity;
/* Statistics of the busiest group */
unsigned long max_load;
unsigned long busiest_load_per_task;
unsigned long busiest_nr_running;
unsigned long busiest_group_capacity;
+ unsigned long busiest_has_capacity;
int group_imb; /* Is there imbalance in this sd */
#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
@@ -2058,6 +2064,7 @@ struct sg_lb_stats {
unsigned long sum_weighted_load; /* Weighted load of group's tasks */
unsigned long group_capacity;
int group_imb; /* Is there an imbalance in the group ? */
+ int group_has_capacity; /* Is there extra capacity in the group? */
};
/**
@@ -2268,7 +2275,13 @@ unsigned long scale_rt_power(int cpu)
u64 total, available;
total = sched_avg_period() + (rq->clock - rq->age_stamp);
- available = total - rq->rt_avg;
+
+ if (unlikely(total < rq->rt_avg)) {
+ /* Ensures that power won't end up being negative */
+ available = 0;
+ } else {
+ available = total - rq->rt_avg;
+ }
if (unlikely((s64)total < SCHED_LOAD_SCALE))
total = SCHED_LOAD_SCALE;
@@ -2378,7 +2391,7 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
int local_group, const struct cpumask *cpus,
int *balance, struct sg_lb_stats *sgs)
{
- unsigned long load, max_cpu_load, min_cpu_load;
+ unsigned long load, max_cpu_load, min_cpu_load, max_nr_running;
int i;
unsigned int balance_cpu = -1, first_idle_cpu = 0;
unsigned long avg_load_per_task = 0;
@@ -2389,6 +2402,7 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
/* Tally up the load of all CPUs in the group */
max_cpu_load = 0;
min_cpu_load = ~0UL;
+ max_nr_running = 0;
for_each_cpu_and(i, sched_group_cpus(group), cpus) {
struct rq *rq = cpu_rq(i);
@@ -2406,8 +2420,10 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
load = target_load(i, load_idx);
} else {
load = source_load(i, load_idx);
- if (load > max_cpu_load)
+ if (load > max_cpu_load) {
max_cpu_load = load;
+ max_nr_running = rq->nr_running;
+ }
if (min_cpu_load > load)
min_cpu_load = load;
}
@@ -2447,13 +2463,15 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
if (sgs->sum_nr_running)
avg_load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
- if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task)
+ if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task && max_nr_running > 1)
sgs->group_imb = 1;
- sgs->group_capacity =
- DIV_ROUND_CLOSEST(group->cpu_power, SCHED_LOAD_SCALE);
+ sgs->group_capacity = DIV_ROUND_CLOSEST(group->cpu_power, SCHED_LOAD_SCALE);
if (!sgs->group_capacity)
sgs->group_capacity = fix_small_capacity(sd, group);
+
+ if (sgs->group_capacity > sgs->sum_nr_running)
+ sgs->group_has_capacity = 1;
}
/**
@@ -2542,9 +2560,14 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
/*
* In case the child domain prefers tasks go to siblings
* first, lower the sg capacity to one so that we'll try
- * and move all the excess tasks away.
+ * and move all the excess tasks away. We lower the capacity
+ * of a group only if the local group has the capacity to fit
+ * these excess tasks, i.e. nr_running < group_capacity. The
+ * extra check prevents the case where you always pull from the
+ * heaviest group when it is already under-utilized (possible
+ * with a large weight task outweighs the tasks on the system).
*/
- if (prefer_sibling)
+ if (prefer_sibling && !local_group && sds->this_has_capacity)
sgs.group_capacity = min(sgs.group_capacity, 1UL);
if (local_group) {
@@ -2552,12 +2575,14 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
sds->this = sg;
sds->this_nr_running = sgs.sum_nr_running;
sds->this_load_per_task = sgs.sum_weighted_load;
+ sds->this_has_capacity = sgs.group_has_capacity;
} else if (update_sd_pick_busiest(sd, sds, sg, &sgs, this_cpu)) {
sds->max_load = sgs.avg_load;
sds->busiest = sg;
sds->busiest_nr_running = sgs.sum_nr_running;
sds->busiest_group_capacity = sgs.group_capacity;
sds->busiest_load_per_task = sgs.sum_weighted_load;
+ sds->busiest_has_capacity = sgs.group_has_capacity;
sds->group_imb = sgs.group_imb;
}
@@ -2754,6 +2779,7 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
return fix_small_imbalance(sds, this_cpu, imbalance);
}
+
/******* find_busiest_group() helpers end here *********************/
/**
@@ -2805,6 +2831,11 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
* 4) This group is more busy than the avg busieness at this
* sched_domain.
* 5) The imbalance is within the specified limit.
+ *
+ * Note: when doing newidle balance, if the local group has excess
+ * capacity (i.e. nr_running < group_capacity) and the busiest group
+ * does not have any capacity, we force a load balance to pull tasks
+ * to the local group. In this case, we skip past checks 3, 4 and 5.
*/
if (!(*balance))
goto ret;
@@ -2816,6 +2847,11 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
if (!sds.busiest || sds.busiest_nr_running == 0)
goto out_balanced;
+ /* SD_BALANCE_NEWIDLE trumps SMP nice when underutilized */
+ if (idle == CPU_NEWLY_IDLE && sds.this_has_capacity &&
+ !sds.busiest_has_capacity)
+ goto force_balance;
+
if (sds.this_load >= sds.max_load)
goto out_balanced;
@@ -2827,6 +2863,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load)
goto out_balanced;
+force_balance:
/* Looks like there is an imbalance. Compute it */
calculate_imbalance(&sds, this_cpu, imbalance);
return sds.busiest;
@@ -3031,7 +3068,14 @@ redo:
if (!ld_moved) {
schedstat_inc(sd, lb_failed[idle]);
- sd->nr_balance_failed++;
+ /*
+ * Increment the failure counter only on periodic balance.
+ * We do not want newidle balance, which can be very
+ * frequent, pollute the failure counter causing
+ * excessive cache_hot migrations and active balances.
+ */
+ if (idle != CPU_NEWLY_IDLE)
+ sd->nr_balance_failed++;
if (need_active_balance(sd, sd_idle, idle, cpu_of(busiest),
this_cpu)) {
@@ -3153,10 +3197,8 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
interval = msecs_to_jiffies(sd->balance_interval);
if (time_after(next_balance, sd->last_balance + interval))
next_balance = sd->last_balance + interval;
- if (pulled_task) {
- this_rq->idle_stamp = 0;
+ if (pulled_task)
break;
- }
}
raw_spin_lock(&this_rq->lock);
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index 83c66e8ad3ee..185f920ec1a2 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -61,3 +61,8 @@ SCHED_FEAT(ASYM_EFF_LOAD, 1)
* release the lock. Decreases scheduling overhead.
*/
SCHED_FEAT(OWNER_SPIN, 1)
+
+/*
+ * Decrement CPU power based on irq activity
+ */
+SCHED_FEAT(NONIRQ_POWER, 1)
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index d10c80ebb67a..bea7d79f7e9c 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -609,7 +609,7 @@ static void update_curr_rt(struct rq *rq)
if (!task_has_rt_policy(curr))
return;
- delta_exec = rq->clock - curr->se.exec_start;
+ delta_exec = rq->clock_task - curr->se.exec_start;
if (unlikely((s64)delta_exec < 0))
delta_exec = 0;
@@ -618,7 +618,7 @@ static void update_curr_rt(struct rq *rq)
curr->se.sum_exec_runtime += delta_exec;
account_group_exec_runtime(curr, delta_exec);
- curr->se.exec_start = rq->clock;
+ curr->se.exec_start = rq->clock_task;
cpuacct_charge(curr, delta_exec);
sched_rt_avg_update(rq, delta_exec);
@@ -960,18 +960,19 @@ select_task_rq_rt(struct rq *rq, struct task_struct *p, int sd_flag, int flags)
* runqueue. Otherwise simply start this RT task
* on its current runqueue.
*
- * We want to avoid overloading runqueues. Even if
- * the RT task is of higher priority than the current RT task.
- * RT tasks behave differently than other tasks. If
- * one gets preempted, we try to push it off to another queue.
- * So trying to keep a preempting RT task on the same
- * cache hot CPU will force the running RT task to
- * a cold CPU. So we waste all the cache for the lower
- * RT task in hopes of saving some of a RT task
- * that is just being woken and probably will have
- * cold cache anyway.
+ * We want to avoid overloading runqueues. If the woken
+ * task is a higher priority, then it will stay on this CPU
+ * and the lower prio task should be moved to another CPU.
+ * Even though this will probably make the lower prio task
+ * lose its cache, we do not want to bounce a higher task
+ * around just because it gave up its CPU, perhaps for a
+ * lock?
+ *
+ * For equal prio tasks, we just let the scheduler sort it out.
*/
if (unlikely(rt_task(rq->curr)) &&
+ (rq->curr->rt.nr_cpus_allowed < 2 ||
+ rq->curr->prio < p->prio) &&
(p->rt.nr_cpus_allowed > 1)) {
int cpu = find_lowest_rq(p);
@@ -1074,7 +1075,7 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq)
} while (rt_rq);
p = rt_task_of(rt_se);
- p->se.exec_start = rq->clock;
+ p->se.exec_start = rq->clock_task;
return p;
}
@@ -1139,7 +1140,7 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)
for_each_leaf_rt_rq(rt_rq, rq) {
array = &rt_rq->active;
idx = sched_find_first_bit(array->bitmap);
- next_idx:
+next_idx:
if (idx >= MAX_RT_PRIO)
continue;
if (next && next->prio < idx)
@@ -1315,7 +1316,7 @@ static int push_rt_task(struct rq *rq)
if (!next_task)
return 0;
- retry:
+retry:
if (unlikely(next_task == rq->curr)) {
WARN_ON(1);
return 0;
@@ -1463,7 +1464,7 @@ static int pull_rt_task(struct rq *this_rq)
* but possible)
*/
}
- skip:
+skip:
double_unlock_balance(this_rq, src_rq);
}
@@ -1491,7 +1492,10 @@ static void task_woken_rt(struct rq *rq, struct task_struct *p)
if (!task_running(rq, p) &&
!test_tsk_need_resched(rq->curr) &&
has_pushable_tasks(rq) &&
- p->rt.nr_cpus_allowed > 1)
+ p->rt.nr_cpus_allowed > 1 &&
+ rt_task(rq->curr) &&
+ (rq->curr->rt.nr_cpus_allowed < 2 ||
+ rq->curr->prio < p->prio))
push_rt_tasks(rq);
}
@@ -1709,7 +1713,7 @@ static void set_curr_task_rt(struct rq *rq)
{
struct task_struct *p = rq->curr;
- p->se.exec_start = rq->clock;
+ p->se.exec_start = rq->clock_task;
/* The running task is never eligible for pushing */
dequeue_pushable_task(rq, p);
diff --git a/kernel/sched_stoptask.c b/kernel/sched_stoptask.c
new file mode 100644
index 000000000000..45bddc0c1048
--- /dev/null
+++ b/kernel/sched_stoptask.c
@@ -0,0 +1,108 @@
+/*
+ * stop-task scheduling class.
+ *
+ * The stop task is the highest priority task in the system, it preempts
+ * everything and will be preempted by nothing.
+ *
+ * See kernel/stop_machine.c
+ */
+
+#ifdef CONFIG_SMP
+static int
+select_task_rq_stop(struct rq *rq, struct task_struct *p,
+ int sd_flag, int flags)
+{
+ return task_cpu(p); /* stop tasks as never migrate */
+}
+#endif /* CONFIG_SMP */
+
+static void
+check_preempt_curr_stop(struct rq *rq, struct task_struct *p, int flags)
+{
+ resched_task(rq->curr); /* we preempt everything */
+}
+
+static struct task_struct *pick_next_task_stop(struct rq *rq)
+{
+ struct task_struct *stop = rq->stop;
+
+ if (stop && stop->state == TASK_RUNNING)
+ return stop;
+
+ return NULL;
+}
+
+static void
+enqueue_task_stop(struct rq *rq, struct task_struct *p, int flags)
+{
+}
+
+static void
+dequeue_task_stop(struct rq *rq, struct task_struct *p, int flags)
+{
+}
+
+static void yield_task_stop(struct rq *rq)
+{
+ BUG(); /* the stop task should never yield, its pointless. */
+}
+
+static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
+{
+}
+
+static void task_tick_stop(struct rq *rq, struct task_struct *curr, int queued)
+{
+}
+
+static void set_curr_task_stop(struct rq *rq)
+{
+}
+
+static void switched_to_stop(struct rq *rq, struct task_struct *p,
+ int running)
+{
+ BUG(); /* its impossible to change to this class */
+}
+
+static void prio_changed_stop(struct rq *rq, struct task_struct *p,
+ int oldprio, int running)
+{
+ BUG(); /* how!?, what priority? */
+}
+
+static unsigned int
+get_rr_interval_stop(struct rq *rq, struct task_struct *task)
+{
+ return 0;
+}
+
+/*
+ * Simple, special scheduling class for the per-CPU stop tasks:
+ */
+static const struct sched_class stop_sched_class = {
+ .next = &rt_sched_class,
+
+ .enqueue_task = enqueue_task_stop,
+ .dequeue_task = dequeue_task_stop,
+ .yield_task = yield_task_stop,
+
+ .check_preempt_curr = check_preempt_curr_stop,
+
+ .pick_next_task = pick_next_task_stop,
+ .put_prev_task = put_prev_task_stop,
+
+#ifdef CONFIG_SMP
+ .select_task_rq = select_task_rq_stop,
+#endif
+
+ .set_curr_task = set_curr_task_stop,
+ .task_tick = task_tick_stop,
+
+ .get_rr_interval = get_rr_interval_stop,
+
+ .prio_changed = prio_changed_stop,
+ .switched_to = switched_to_stop,
+
+ /* no .task_new for stop tasks */
+};
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 07b4f1b1a73a..79ee8f1fc0e7 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -77,11 +77,21 @@ void wakeup_softirqd(void)
}
/*
+ * preempt_count and SOFTIRQ_OFFSET usage:
+ * - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving
+ * softirq processing.
+ * - preempt_count is changed by SOFTIRQ_DISABLE_OFFSET (= 2 * SOFTIRQ_OFFSET)
+ * on local_bh_disable or local_bh_enable.
+ * This lets us distinguish between whether we are currently processing
+ * softirq and whether we just have bh disabled.
+ */
+
+/*
* This one is for softirq.c-internal use,
* where hardirqs are disabled legitimately:
*/
#ifdef CONFIG_TRACE_IRQFLAGS
-static void __local_bh_disable(unsigned long ip)
+static void __local_bh_disable(unsigned long ip, unsigned int cnt)
{
unsigned long flags;
@@ -95,32 +105,43 @@ static void __local_bh_disable(unsigned long ip)
* We must manually increment preempt_count here and manually
* call the trace_preempt_off later.
*/
- preempt_count() += SOFTIRQ_OFFSET;
+ preempt_count() += cnt;
/*
* Were softirqs turned off above:
*/
- if (softirq_count() == SOFTIRQ_OFFSET)
+ if (softirq_count() == cnt)
trace_softirqs_off(ip);
raw_local_irq_restore(flags);
- if (preempt_count() == SOFTIRQ_OFFSET)
+ if (preempt_count() == cnt)
trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
}
#else /* !CONFIG_TRACE_IRQFLAGS */
-static inline void __local_bh_disable(unsigned long ip)
+static inline void __local_bh_disable(unsigned long ip, unsigned int cnt)
{
- add_preempt_count(SOFTIRQ_OFFSET);
+ add_preempt_count(cnt);
barrier();
}
#endif /* CONFIG_TRACE_IRQFLAGS */
void local_bh_disable(void)
{
- __local_bh_disable((unsigned long)__builtin_return_address(0));
+ __local_bh_disable((unsigned long)__builtin_return_address(0),
+ SOFTIRQ_DISABLE_OFFSET);
}
EXPORT_SYMBOL(local_bh_disable);
+static void __local_bh_enable(unsigned int cnt)
+{
+ WARN_ON_ONCE(in_irq());
+ WARN_ON_ONCE(!irqs_disabled());
+
+ if (softirq_count() == cnt)
+ trace_softirqs_on((unsigned long)__builtin_return_address(0));
+ sub_preempt_count(cnt);
+}
+
/*
* Special-case - softirqs can safely be enabled in
* cond_resched_softirq(), or by __do_softirq(),
@@ -128,12 +149,7 @@ EXPORT_SYMBOL(local_bh_disable);
*/
void _local_bh_enable(void)
{
- WARN_ON_ONCE(in_irq());
- WARN_ON_ONCE(!irqs_disabled());
-
- if (softirq_count() == SOFTIRQ_OFFSET)
- trace_softirqs_on((unsigned long)__builtin_return_address(0));
- sub_preempt_count(SOFTIRQ_OFFSET);
+ __local_bh_enable(SOFTIRQ_DISABLE_OFFSET);
}
EXPORT_SYMBOL(_local_bh_enable);
@@ -147,13 +163,13 @@ static inline void _local_bh_enable_ip(unsigned long ip)
/*
* Are softirqs going to be turned on now:
*/
- if (softirq_count() == SOFTIRQ_OFFSET)
+ if (softirq_count() == SOFTIRQ_DISABLE_OFFSET)
trace_softirqs_on(ip);
/*
* Keep preemption disabled until we are done with
* softirq processing:
*/
- sub_preempt_count(SOFTIRQ_OFFSET - 1);
+ sub_preempt_count(SOFTIRQ_DISABLE_OFFSET - 1);
if (unlikely(!in_interrupt() && local_softirq_pending()))
do_softirq();
@@ -198,7 +214,8 @@ asmlinkage void __do_softirq(void)
pending = local_softirq_pending();
account_system_vtime(current);
- __local_bh_disable((unsigned long)__builtin_return_address(0));
+ __local_bh_disable((unsigned long)__builtin_return_address(0),
+ SOFTIRQ_OFFSET);
lockdep_softirq_enter();
cpu = smp_processor_id();
@@ -245,7 +262,7 @@ restart:
lockdep_softirq_exit();
account_system_vtime(current);
- _local_bh_enable();
+ __local_bh_enable(SOFTIRQ_OFFSET);
}
#ifndef __ARCH_HAS_DO_SOFTIRQ
@@ -279,10 +296,16 @@ void irq_enter(void)
rcu_irq_enter();
if (idle_cpu(cpu) && !in_interrupt()) {
- __irq_enter();
+ /*
+ * Prevent raise_softirq from needlessly waking up ksoftirqd
+ * here, as softirq will be serviced on return from interrupt.
+ */
+ local_bh_disable();
tick_check_idle(cpu);
- } else
- __irq_enter();
+ _local_bh_enable();
+ }
+
+ __irq_enter();
}
#ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED
@@ -696,6 +719,7 @@ static int run_ksoftirqd(void * __bind_cpu)
{
set_current_state(TASK_INTERRUPTIBLE);
+ current->flags |= PF_KSOFTIRQD;
while (!kthread_should_stop()) {
preempt_disable();
if (!local_softirq_pending()) {
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 4372ccb25127..090c28812ce1 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -287,11 +287,12 @@ repeat:
goto repeat;
}
+extern void sched_set_stop_task(int cpu, struct task_struct *stop);
+
/* manage stopper for a cpu, mostly lifted from sched migration thread mgmt */
static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
- struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
unsigned int cpu = (unsigned long)hcpu;
struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
struct task_struct *p;
@@ -304,13 +305,13 @@ static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb,
cpu);
if (IS_ERR(p))
return NOTIFY_BAD;
- sched_setscheduler_nocheck(p, SCHED_FIFO, &param);
get_task_struct(p);
+ kthread_bind(p, cpu);
+ sched_set_stop_task(cpu, p);
stopper->thread = p;
break;
case CPU_ONLINE:
- kthread_bind(stopper->thread, cpu);
/* strictly unnecessary, as first user will wake it */
wake_up_process(stopper->thread);
/* mark enabled */
@@ -325,6 +326,7 @@ static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb,
{
struct cpu_stop_work *work;
+ sched_set_stop_task(cpu, NULL);
/* kill the stopper */
kthread_stop(stopper->thread);
/* drain remaining works */
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 78ef2c5e130b..37dff78e9cb1 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -123,7 +123,7 @@ static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
* calls by looking at the number of nested bh disable calls because
* softirqs always disables bh.
*/
- if (softirq_count() != SOFTIRQ_OFFSET) {
+ if (in_serving_softirq()) {
/* If there is an sk_classid we'll use that. */
if (!skb->sk)
return -1;
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-05 08:05:52 +0000