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authorLinus Torvalds <torvalds@linux-foundation.org>2009-09-17 21:00:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-17 21:00:02 -0700
commitdcbf77b9e86e1726f5fbd01bb98820dac06d456e (patch)
tree2f0b728ce70c03e1d0e3461e8a3c3d1fbe68fb90
parentca043a66ae48c74fa628ec92178f7a54f5b9a106 (diff)
parent29cd8bae396583a2ee9a3340db8c5102acf9f6fd (diff)
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (37 commits) sched: Fix SD_POWERSAVING_BALANCE|SD_PREFER_LOCAL vs SD_WAKE_AFFINE sched: Stop buddies from hogging the system sched: Add new wakeup preemption mode: WAKEUP_RUNNING sched: Fix TASK_WAKING & loadaverage breakage sched: Disable wakeup balancing sched: Rename flags to wake_flags sched: Clean up the load_idx selection in select_task_rq_fair sched: Optimize cgroup vs wakeup a bit sched: x86: Name old_perf in a unique way sched: Implement a gentler fair-sleepers feature sched: Add SD_PREFER_LOCAL sched: Add a few SYNC hint knobs to play with sched: Fix sync wakeups again sched: Add WF_FORK sched: Rename sync arguments sched: Rename select_task_rq() argument sched: Feature to disable APERF/MPERF cpu_power x86: sched: Provide arch implementations using aperf/mperf x86: Add generic aperf/mperf code x86: Move APERF/MPERF into a X86_FEATURE ... Fix up trivial conflict in arch/x86/include/asm/processor.h due to nearby addition of amd_get_nb_id() declaration from the EDAC merge.
-rw-r--r--arch/ia64/include/asm/topology.h17
-rw-r--r--arch/mips/include/asm/mach-ip27/topology.h1
-rw-r--r--arch/powerpc/include/asm/topology.h9
-rw-r--r--arch/sh/include/asm/topology.h10
-rw-r--r--arch/sparc/include/asm/topology_64.h7
-rw-r--r--arch/x86/include/asm/cpufeature.h1
-rw-r--r--arch/x86/include/asm/processor.h30
-rw-r--r--arch/x86/include/asm/topology.h14
-rw-r--r--arch/x86/kernel/cpu/Makefile2
-rw-r--r--arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c88
-rw-r--r--arch/x86/kernel/cpu/intel.c6
-rw-r--r--arch/x86/kernel/cpu/sched.c55
-rw-r--r--include/linux/sched.h23
-rw-r--r--include/linux/topology.h32
-rw-r--r--include/linux/wait.h4
-rw-r--r--kernel/sched.c444
-rw-r--r--kernel/sched_debug.c1
-rw-r--r--kernel/sched_fair.c414
-rw-r--r--kernel/sched_features.h122
-rw-r--r--kernel/sched_idletask.c4
-rw-r--r--kernel/sched_rt.c7
21 files changed, 688 insertions, 603 deletions
diff --git a/arch/ia64/include/asm/topology.h b/arch/ia64/include/asm/topology.h
index 7b4c8c70b2d1..d0141fbf51d0 100644
--- a/arch/ia64/include/asm/topology.h
+++ b/arch/ia64/include/asm/topology.h
@@ -61,12 +61,13 @@ void build_cpu_to_node_map(void);
.cache_nice_tries = 2, \
.busy_idx = 2, \
.idle_idx = 1, \
- .newidle_idx = 2, \
- .wake_idx = 1, \
- .forkexec_idx = 1, \
+ .newidle_idx = 0, \
+ .wake_idx = 0, \
+ .forkexec_idx = 0, \
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_NEWIDLE \
| SD_BALANCE_EXEC \
+ | SD_BALANCE_FORK \
| SD_WAKE_AFFINE, \
.last_balance = jiffies, \
.balance_interval = 1, \
@@ -85,14 +86,14 @@ void build_cpu_to_node_map(void);
.cache_nice_tries = 2, \
.busy_idx = 3, \
.idle_idx = 2, \
- .newidle_idx = 2, \
- .wake_idx = 1, \
- .forkexec_idx = 1, \
+ .newidle_idx = 0, \
+ .wake_idx = 0, \
+ .forkexec_idx = 0, \
.flags = SD_LOAD_BALANCE \
+ | SD_BALANCE_NEWIDLE \
| SD_BALANCE_EXEC \
| SD_BALANCE_FORK \
- | SD_SERIALIZE \
- | SD_WAKE_BALANCE, \
+ | SD_SERIALIZE, \
.last_balance = jiffies, \
.balance_interval = 64, \
.nr_balance_failed = 0, \
diff --git a/arch/mips/include/asm/mach-ip27/topology.h b/arch/mips/include/asm/mach-ip27/topology.h
index 07547231e078..230591707005 100644
--- a/arch/mips/include/asm/mach-ip27/topology.h
+++ b/arch/mips/include/asm/mach-ip27/topology.h
@@ -48,7 +48,6 @@ extern unsigned char __node_distances[MAX_COMPACT_NODES][MAX_COMPACT_NODES];
.cache_nice_tries = 1, \
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_EXEC \
- | SD_WAKE_BALANCE, \
.last_balance = jiffies, \
.balance_interval = 1, \
.nr_balance_failed = 0, \
diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h
index 054a16d68082..394edcbcce71 100644
--- a/arch/powerpc/include/asm/topology.h
+++ b/arch/powerpc/include/asm/topology.h
@@ -57,14 +57,13 @@ static inline int pcibus_to_node(struct pci_bus *bus)
.cache_nice_tries = 1, \
.busy_idx = 3, \
.idle_idx = 1, \
- .newidle_idx = 2, \
- .wake_idx = 1, \
+ .newidle_idx = 0, \
+ .wake_idx = 0, \
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_EXEC \
+ | SD_BALANCE_FORK \
| SD_BALANCE_NEWIDLE \
- | SD_WAKE_IDLE \
- | SD_SERIALIZE \
- | SD_WAKE_BALANCE, \
+ | SD_SERIALIZE, \
.last_balance = jiffies, \
.balance_interval = 1, \
.nr_balance_failed = 0, \
diff --git a/arch/sh/include/asm/topology.h b/arch/sh/include/asm/topology.h
index b69ee850906d..f8c40cc65054 100644
--- a/arch/sh/include/asm/topology.h
+++ b/arch/sh/include/asm/topology.h
@@ -15,14 +15,14 @@
.cache_nice_tries = 2, \
.busy_idx = 3, \
.idle_idx = 2, \
- .newidle_idx = 2, \
- .wake_idx = 1, \
- .forkexec_idx = 1, \
+ .newidle_idx = 0, \
+ .wake_idx = 0, \
+ .forkexec_idx = 0, \
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_FORK \
| SD_BALANCE_EXEC \
- | SD_SERIALIZE \
- | SD_WAKE_BALANCE, \
+ | SD_BALANCE_NEWIDLE \
+ | SD_SERIALIZE, \
.last_balance = jiffies, \
.balance_interval = 1, \
.nr_balance_failed = 0, \
diff --git a/arch/sparc/include/asm/topology_64.h b/arch/sparc/include/asm/topology_64.h
index e5ea8d332421..26cd25c08399 100644
--- a/arch/sparc/include/asm/topology_64.h
+++ b/arch/sparc/include/asm/topology_64.h
@@ -52,13 +52,12 @@ static inline int pcibus_to_node(struct pci_bus *pbus)
.busy_idx = 3, \
.idle_idx = 2, \
.newidle_idx = 0, \
- .wake_idx = 1, \
- .forkexec_idx = 1, \
+ .wake_idx = 0, \
+ .forkexec_idx = 0, \
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_FORK \
| SD_BALANCE_EXEC \
- | SD_SERIALIZE \
- | SD_WAKE_BALANCE, \
+ | SD_SERIALIZE, \
.last_balance = jiffies, \
.balance_interval = 1, \
}
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 847fee6493a2..9cfc88b97742 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -96,6 +96,7 @@
#define X86_FEATURE_CLFLUSH_MONITOR (3*32+25) /* "" clflush reqd with monitor */
#define X86_FEATURE_EXTD_APICID (3*32+26) /* has extended APICID (8 bits) */
#define X86_FEATURE_AMD_DCM (3*32+27) /* multi-node processor */
+#define X86_FEATURE_APERFMPERF (3*32+28) /* APERFMPERF */
/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* "pni" SSE-3 */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 42a3f936dadc..c3429e8b2424 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -27,6 +27,7 @@ struct mm_struct;
#include <linux/cpumask.h>
#include <linux/cache.h>
#include <linux/threads.h>
+#include <linux/math64.h>
#include <linux/init.h>
/*
@@ -1022,4 +1023,33 @@ extern int set_tsc_mode(unsigned int val);
extern int amd_get_nb_id(int cpu);
+struct aperfmperf {
+ u64 aperf, mperf;
+};
+
+static inline void get_aperfmperf(struct aperfmperf *am)
+{
+ WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_APERFMPERF));
+
+ rdmsrl(MSR_IA32_APERF, am->aperf);
+ rdmsrl(MSR_IA32_MPERF, am->mperf);
+}
+
+#define APERFMPERF_SHIFT 10
+
+static inline
+unsigned long calc_aperfmperf_ratio(struct aperfmperf *old,
+ struct aperfmperf *new)
+{
+ u64 aperf = new->aperf - old->aperf;
+ u64 mperf = new->mperf - old->mperf;
+ unsigned long ratio = aperf;
+
+ mperf >>= APERFMPERF_SHIFT;
+ if (mperf)
+ ratio = div64_u64(aperf, mperf);
+
+ return ratio;
+}
+
#endif /* _ASM_X86_PROCESSOR_H */
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index 26d06e052a18..6f0695d744bf 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -116,15 +116,11 @@ extern unsigned long node_remap_size[];
# define SD_CACHE_NICE_TRIES 1
# define SD_IDLE_IDX 1
-# define SD_NEWIDLE_IDX 2
-# define SD_FORKEXEC_IDX 0
#else
# define SD_CACHE_NICE_TRIES 2
# define SD_IDLE_IDX 2
-# define SD_NEWIDLE_IDX 2
-# define SD_FORKEXEC_IDX 1
#endif
@@ -137,22 +133,20 @@ extern unsigned long node_remap_size[];
.cache_nice_tries = SD_CACHE_NICE_TRIES, \
.busy_idx = 3, \
.idle_idx = SD_IDLE_IDX, \
- .newidle_idx = SD_NEWIDLE_IDX, \
- .wake_idx = 1, \
- .forkexec_idx = SD_FORKEXEC_IDX, \
+ .newidle_idx = 0, \
+ .wake_idx = 0, \
+ .forkexec_idx = 0, \
\
.flags = 1*SD_LOAD_BALANCE \
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
- | 0*SD_WAKE_IDLE \
+ | 0*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
- | 1*SD_WAKE_BALANCE \
| 0*SD_SHARE_CPUPOWER \
| 0*SD_POWERSAVINGS_BALANCE \
| 0*SD_SHARE_PKG_RESOURCES \
| 1*SD_SERIALIZE \
- | 1*SD_WAKE_IDLE_FAR \
| 0*SD_PREFER_SIBLING \
, \
.last_balance = jiffies, \
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index c1f253dac155..8dd30638fe44 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -13,7 +13,7 @@ CFLAGS_common.o := $(nostackp)
obj-y := intel_cacheinfo.o addon_cpuid_features.o
obj-y += proc.o capflags.o powerflags.o common.o
-obj-y += vmware.o hypervisor.o
+obj-y += vmware.o hypervisor.o sched.o
obj-$(CONFIG_X86_32) += bugs.o cmpxchg.o
obj-$(CONFIG_X86_64) += bugs_64.o
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index ae9b503220ca..4109679863c1 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -60,7 +60,6 @@ enum {
};
#define INTEL_MSR_RANGE (0xffff)
-#define CPUID_6_ECX_APERFMPERF_CAPABILITY (0x1)
struct acpi_cpufreq_data {
struct acpi_processor_performance *acpi_data;
@@ -71,11 +70,7 @@ struct acpi_cpufreq_data {
static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);
-struct acpi_msr_data {
- u64 saved_aperf, saved_mperf;
-};
-
-static DEFINE_PER_CPU(struct acpi_msr_data, msr_data);
+static DEFINE_PER_CPU(struct aperfmperf, old_perf);
DEFINE_TRACE(power_mark);
@@ -244,23 +239,12 @@ static u32 get_cur_val(const struct cpumask *mask)
return cmd.val;
}
-struct perf_pair {
- union {
- struct {
- u32 lo;
- u32 hi;
- } split;
- u64 whole;
- } aperf, mperf;
-};
-
/* Called via smp_call_function_single(), on the target CPU */
static void read_measured_perf_ctrs(void *_cur)
{
- struct perf_pair *cur = _cur;
+ struct aperfmperf *am = _cur;
- rdmsr(MSR_IA32_APERF, cur->aperf.split.lo, cur->aperf.split.hi);
- rdmsr(MSR_IA32_MPERF, cur->mperf.split.lo, cur->mperf.split.hi);
+ get_aperfmperf(am);
}
/*
@@ -279,63 +263,17 @@ static void read_measured_perf_ctrs(void *_cur)
static unsigned int get_measured_perf(struct cpufreq_policy *policy,
unsigned int cpu)
{
- struct perf_pair readin, cur;
- unsigned int perf_percent;
+ struct aperfmperf perf;
+ unsigned long ratio;
unsigned int retval;
- if (smp_call_function_single(cpu, read_measured_perf_ctrs, &readin, 1))
+ if (smp_call_function_single(cpu, read_measured_perf_ctrs, &perf, 1))
return 0;
- cur.aperf.whole = readin.aperf.whole -
- per_cpu(msr_data, cpu).saved_aperf;
- cur.mperf.whole = readin.mperf.whole -
- per_cpu(msr_data, cpu).saved_mperf;
- per_cpu(msr_data, cpu).saved_aperf = readin.aperf.whole;
- per_cpu(msr_data, cpu).saved_mperf = readin.mperf.whole;
-
-#ifdef __i386__
- /*
- * We dont want to do 64 bit divide with 32 bit kernel
- * Get an approximate value. Return failure in case we cannot get
- * an approximate value.
- */
- if (unlikely(cur.aperf.split.hi || cur.mperf.split.hi)) {
- int shift_count;
- u32 h;
-
- h = max_t(u32, cur.aperf.split.hi, cur.mperf.split.hi);
- shift_count = fls(h);
-
- cur.aperf.whole >>= shift_count;
- cur.mperf.whole >>= shift_count;
- }
-
- if (((unsigned long)(-1) / 100) < cur.aperf.split.lo) {
- int shift_count = 7;
- cur.aperf.split.lo >>= shift_count;
- cur.mperf.split.lo >>= shift_count;
- }
-
- if (cur.aperf.split.lo && cur.mperf.split.lo)
- perf_percent = (cur.aperf.split.lo * 100) / cur.mperf.split.lo;
- else
- perf_percent = 0;
+ ratio = calc_aperfmperf_ratio(&per_cpu(old_perf, cpu), &perf);
+ per_cpu(old_perf, cpu) = perf;
-#else
- if (unlikely(((unsigned long)(-1) / 100) < cur.aperf.whole)) {
- int shift_count = 7;
- cur.aperf.whole >>= shift_count;
- cur.mperf.whole >>= shift_count;
- }
-
- if (cur.aperf.whole && cur.mperf.whole)
- perf_percent = (cur.aperf.whole * 100) / cur.mperf.whole;
- else
- perf_percent = 0;
-
-#endif
-
- retval = (policy->cpuinfo.max_freq * perf_percent) / 100;
+ retval = (policy->cpuinfo.max_freq * ratio) >> APERFMPERF_SHIFT;
return retval;
}
@@ -731,12 +669,8 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
acpi_processor_notify_smm(THIS_MODULE);
/* Check for APERF/MPERF support in hardware */
- if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
- unsigned int ecx;
- ecx = cpuid_ecx(6);
- if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
- acpi_cpufreq_driver.getavg = get_measured_perf;
- }
+ if (cpu_has(c, X86_FEATURE_APERFMPERF))
+ acpi_cpufreq_driver.getavg = get_measured_perf;
dprintk("CPU%u - ACPI performance management activated.\n", cpu);
for (i = 0; i < perf->state_count; i++)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 80a722a071b5..40e1835b35e8 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -350,6 +350,12 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
}
+ if (c->cpuid_level > 6) {
+ unsigned ecx = cpuid_ecx(6);
+ if (ecx & 0x01)
+ set_cpu_cap(c, X86_FEATURE_APERFMPERF);
+ }
+
if (cpu_has_xmm2)
set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
if (cpu_has_ds) {
diff --git a/arch/x86/kernel/cpu/sched.c b/arch/x86/kernel/cpu/sched.c
new file mode 100644
index 000000000000..a640ae5ad201
--- /dev/null
+++ b/arch/x86/kernel/cpu/sched.c
@@ -0,0 +1,55 @@
+#include <linux/sched.h>
+#include <linux/math64.h>
+#include <linux/percpu.h>
+#include <linux/irqflags.h>
+
+#include <asm/cpufeature.h>
+#include <asm/processor.h>
+
+#ifdef CONFIG_SMP
+
+static DEFINE_PER_CPU(struct aperfmperf, old_perf_sched);
+
+static unsigned long scale_aperfmperf(void)
+{
+ struct aperfmperf val, *old = &__get_cpu_var(old_perf_sched);
+ unsigned long ratio, flags;
+
+ local_irq_save(flags);
+ get_aperfmperf(&val);
+ local_irq_restore(flags);
+
+ ratio = calc_aperfmperf_ratio(old, &val);
+ *old = val;
+
+ return ratio;
+}
+
+unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu)
+{
+ /*
+ * do aperf/mperf on the cpu level because it includes things
+ * like turbo mode, which are relevant to full cores.
+ */
+ if (boot_cpu_has(X86_FEATURE_APERFMPERF))
+ return scale_aperfmperf();
+
+ /*
+ * maybe have something cpufreq here
+ */
+
+ return default_scale_freq_power(sd, cpu);
+}
+
+unsigned long arch_scale_smt_power(struct sched_domain *sd, int cpu)
+{
+ /*
+ * aperf/mperf already includes the smt gain
+ */
+ if (boot_cpu_has(X86_FEATURE_APERFMPERF))
+ return SCHED_LOAD_SCALE;
+
+ return default_scale_smt_power(sd, cpu);
+}
+
+#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f3d74bd04d18..8af3d249170e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -190,6 +190,7 @@ extern unsigned long long time_sync_thresh;
/* in tsk->state again */
#define TASK_DEAD 64
#define TASK_WAKEKILL 128
+#define TASK_WAKING 256
/* Convenience macros for the sake of set_task_state */
#define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
@@ -802,14 +803,14 @@ enum cpu_idle_type {
#define SD_BALANCE_NEWIDLE 0x0002 /* Balance when about to become idle */
#define SD_BALANCE_EXEC 0x0004 /* Balance on exec */
#define SD_BALANCE_FORK 0x0008 /* Balance on fork, clone */
-#define SD_WAKE_IDLE 0x0010 /* Wake to idle CPU on task wakeup */
+#define SD_BALANCE_WAKE 0x0010 /* Balance on wakeup */
#define SD_WAKE_AFFINE 0x0020 /* Wake task to waking CPU */
-#define SD_WAKE_BALANCE 0x0040 /* Perform balancing at task wakeup */
+#define SD_PREFER_LOCAL 0x0040 /* Prefer to keep tasks local to this domain */
#define SD_SHARE_CPUPOWER 0x0080 /* Domain members share cpu power */
#define SD_POWERSAVINGS_BALANCE 0x0100 /* Balance for power savings */
#define SD_SHARE_PKG_RESOURCES 0x0200 /* Domain members share cpu pkg resources */
#define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */
-#define SD_WAKE_IDLE_FAR 0x0800 /* Gain latency sacrificing cache hit */
+
#define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */
enum powersavings_balance_level {
@@ -991,6 +992,9 @@ static inline int test_sd_parent(struct sched_domain *sd, int flag)
return 0;
}
+unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
+unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
+
#else /* CONFIG_SMP */
struct sched_domain_attr;
@@ -1002,6 +1006,7 @@ partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
}
#endif /* !CONFIG_SMP */
+
struct io_context; /* See blkdev.h */
@@ -1019,6 +1024,12 @@ struct uts_namespace;
struct rq;
struct sched_domain;
+/*
+ * wake flags
+ */
+#define WF_SYNC 0x01 /* waker goes to sleep after wakup */
+#define WF_FORK 0x02 /* child wakeup after fork */
+
struct sched_class {
const struct sched_class *next;
@@ -1026,13 +1037,13 @@ struct sched_class {
void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep);
void (*yield_task) (struct rq *rq);
- void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int sync);
+ void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
struct task_struct * (*pick_next_task) (struct rq *rq);
void (*put_prev_task) (struct rq *rq, struct task_struct *p);
#ifdef CONFIG_SMP
- int (*select_task_rq)(struct task_struct *p, int sync);
+ int (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
unsigned long (*load_balance) (struct rq *this_rq, int this_cpu,
struct rq *busiest, unsigned long max_load_move,
@@ -1102,6 +1113,8 @@ struct sched_entity {
u64 start_runtime;
u64 avg_wakeup;
+ u64 avg_running;
+
#ifdef CONFIG_SCHEDSTATS
u64 wait_start;
u64 wait_max;
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 85e8cf7d393c..809b26c07090 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -95,14 +95,12 @@ int arch_update_cpu_topology(void);
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
- | 0*SD_WAKE_IDLE \
+ | 0*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
- | 1*SD_WAKE_BALANCE \
| 1*SD_SHARE_CPUPOWER \
| 0*SD_POWERSAVINGS_BALANCE \
| 0*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
- | 0*SD_WAKE_IDLE_FAR \
| 0*SD_PREFER_SIBLING \
, \
.last_balance = jiffies, \
@@ -122,20 +120,19 @@ int arch_update_cpu_topology(void);
.imbalance_pct = 125, \
.cache_nice_tries = 1, \
.busy_idx = 2, \
- .wake_idx = 1, \
- .forkexec_idx = 1, \
+ .wake_idx = 0, \
+ .forkexec_idx = 0, \
\
.flags = 1*SD_LOAD_BALANCE \
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
- | 1*SD_WAKE_IDLE \
+ | 0*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
- | 1*SD_WAKE_BALANCE \
+ | 1*SD_PREFER_LOCAL \
| 0*SD_SHARE_CPUPOWER \
| 1*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
- | 0*SD_WAKE_IDLE_FAR \
| sd_balance_for_mc_power() \
| sd_power_saving_flags() \
, \
@@ -155,21 +152,20 @@ int arch_update_cpu_topology(void);
.cache_nice_tries = 1, \
.busy_idx = 2, \
.idle_idx = 1, \
- .newidle_idx = 2, \
- .wake_idx = 1, \
- .forkexec_idx = 1, \
+ .newidle_idx = 0, \
+ .wake_idx = 0, \
+ .forkexec_idx = 0, \
\
.flags = 1*SD_LOAD_BALANCE \
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
- | 1*SD_WAKE_IDLE \
- | 0*SD_WAKE_AFFINE \
- | 1*SD_WAKE_BALANCE \
+ | 0*SD_BALANCE_WAKE \
+ | 1*SD_WAKE_AFFINE \
+ | 1*SD_PREFER_LOCAL \
| 0*SD_SHARE_CPUPOWER \
| 0*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
- | 0*SD_WAKE_IDLE_FAR \
| sd_balance_for_package_power() \
| sd_power_saving_flags() \
, \
@@ -191,14 +187,12 @@ int arch_update_cpu_topology(void);
| 1*SD_BALANCE_NEWIDLE \
| 0*SD_BALANCE_EXEC \
| 0*SD_BALANCE_FORK \
- | 0*SD_WAKE_IDLE \
- | 1*SD_WAKE_AFFINE \
- | 0*SD_WAKE_BALANCE \
+ | 0*SD_BALANCE_WAKE \
+ | 0*SD_WAKE_AFFINE \
| 0*SD_SHARE_CPUPOWER \
| 0*SD_POWERSAVINGS_BALANCE \
| 0*SD_SHARE_PKG_RESOURCES \
| 1*SD_SERIALIZE \
- | 1*SD_WAKE_IDLE_FAR \
| 0*SD_PREFER_SIBLING \
, \
.last_balance = jiffies, \
diff --git a/include/linux/wait.h b/include/linux/wait.h
index cf3c2f5dba51..a48e16b77d5e 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -26,8 +26,8 @@
#include <asm/current.h>
typedef struct __wait_queue wait_queue_t;
-typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync, void *key);
-int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
+typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
+int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);
struct __wait_queue {
unsigned int flags;
diff --git a/kernel/sched.c b/kernel/sched.c
index d9db3fb17573..faf4d463bbff 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -119,8 +119,6 @@
*/
#define RUNTIME_INF ((u64)~0ULL)
-static void double_rq_lock(struct rq *rq1, struct rq *rq2);
-
static inline int rt_policy(int policy)
{
if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR))
@@ -378,13 +376,6 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
#else
-#ifdef CONFIG_SMP
-static int root_task_group_empty(void)
-{
- return 1;
-}
-#endif
-
static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
static inline struct task_group *task_group(struct task_struct *p)
{
@@ -514,14 +505,6 @@ struct root_domain {
#ifdef CONFIG_SMP
struct cpupri cpupri;
#endif
-#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
- /*
- * Preferred wake up cpu nominated by sched_mc balance that will be
- * used when most cpus are idle in the system indicating overall very
- * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2)
- */
- unsigned int sched_mc_preferred_wakeup_cpu;
-#endif
};
/*
@@ -646,9 +629,10 @@ struct rq {
static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
-static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync)
+static inline
+void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
{
- rq->curr->sched_class->check_preempt_curr(rq, p, sync);
+ rq->curr->sched_class->check_preempt_curr(rq, p, flags);
}
static inline int cpu_of(struct rq *rq)
@@ -1509,8 +1493,65 @@ static int tg_nop(struct task_group *tg, void *data)
#endif
#ifdef CONFIG_SMP
-static unsigned long source_load(int cpu, int type);
-static unsigned long target_load(int cpu, int type);
+/* Used instead of source_load when we know the type == 0 */
+static unsigned long weighted_cpuload(const int cpu)
+{
+ return cpu_rq(cpu)->load.weight;
+}
+
+/*
+ * Return a low guess at the load of a migration-source cpu weighted
+ * according to the scheduling class and "nice" value.
+ *
+ * We want to under-estimate the load of migration sources, to
+ * balance conservatively.
+ */
+static unsigned long source_load(int cpu, int type)
+{
+ struct rq *rq = cpu_rq(cpu);
+ unsigned long total = weighted_cpuload(cpu);
+
+ if (type == 0 || !sched_feat(LB_BIAS))
+ return total;
+
+ return min(rq->cpu_load[type-1], total);
+}
+
+/*
+ * Return a high guess at the load of a migration-target cpu weighted
+ * according to the scheduling class and "nice" value.
+ */
+static unsigned long target_load(int cpu, int type)
+{
+ struct rq *rq = cpu_rq(cpu);
+ unsigned long total = weighted_cpuload(cpu);
+
+ if (type == 0 || !sched_feat(LB_BIAS))
+ return total;
+
+ return max(rq->cpu_load[type-1], total);
+}
+
+static struct sched_group *group_of(int cpu)
+{
+ struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd);
+
+ if (!sd)
+ return NULL;
+
+ return sd->groups;
+}
+
+static unsigned long power_of(int cpu)
+{
+ struct sched_group *group = group_of(cpu);
+
+ if (!group)
+ return SCHED_LOAD_SCALE;
+
+ return group->cpu_power;
+}
+
static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
static unsigned long cpu_avg_load_per_task(int cpu)
@@ -1695,6 +1736,8 @@ static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd)
#ifdef CONFIG_PREEMPT
+static void double_rq_lock(struct rq *rq1, struct rq *rq2);
+
/*
* fair double_lock_balance: Safely acquires both rq->locks in a fair
* way at the expense of forcing extra atomic operations in all
@@ -1959,13 +2002,6 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p,
}
#ifdef CONFIG_SMP
-
-/* Used instead of source_load when we know the type == 0 */
-static unsigned long weighted_cpuload(const int cpu)
-{
- return cpu_rq(cpu)->load.weight;
-}
-
/*
* Is this task likely cache-hot:
*/
@@ -2239,185 +2275,6 @@ void kick_process(struct task_struct *p)
preempt_enable();
}
EXPORT_SYMBOL_GPL(kick_process);
-
-/*
- * Return a low guess at the load of a migration-source cpu weighted
- * according to the scheduling class and "nice" value.
- *
- * We want to under-estimate the load of migration sources, to
- * balance conservatively.
- */
-static unsigned long source_load(int cpu, int type)
-{
- struct rq *rq = cpu_rq(cpu);
- unsigned long total = weighted_cpuload(cpu);
-
- if (type == 0 || !sched_feat(LB_BIAS))
- return total;
-
- return min(rq->cpu_load[type-1], total);
-}
-
-/*
- * Return a high guess at the load of a migration-target cpu weighted
- * according to the scheduling class and "nice" value.
- */
-static unsigned long target_load(int cpu, int type)
-{
- struct rq *rq = cpu_rq(cpu);
- unsigned long total = weighted_cpuload(cpu);
-
- if (type == 0 || !sched_feat(LB_BIAS))
- return total;
-
- return max(rq->cpu_load[type-1], total);
-}
-
-/*
- * find_idlest_group finds and returns the least busy CPU group within the
- * domain.
- */
-static struct sched_group *
-find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
-{
- struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups;
- unsigned long min_load = ULONG_MAX, this_load = 0;
- int load_idx = sd->forkexec_idx;
- int imbalance = 100 + (sd->imbalance_pct-100)/2;
-
- do {
- unsigned long load, avg_load;
- int local_group;
- int i;
-
- /* Skip over this group if it has no CPUs allowed */
- if (!cpumask_intersects(sched_group_cpus(group),
- &p->cpus_allowed))
- continue;
-
- local_group = cpumask_test_cpu(this_cpu,
- sched_group_cpus(group));
-
- /* Tally up the load of all CPUs in the group */
- avg_load = 0;
-
- for_each_cpu(i, sched_group_cpus(group)) {
- /* Bias balancing toward cpus of our domain */
- if (local_group)
- load = source_load(i, load_idx);
- else
- load = target_load(i, load_idx);
-
- avg_load += load;
- }
-
- /* Adjust by relative CPU power of the group */
- avg_load = (avg_load * SCHED_LOAD_SCALE) / group->cpu_power;
-
- if (local_group) {
- this_load = avg_load;
- this = group;
- } else if (avg_load < min_load) {
- min_load = avg_load;
- idlest = group;
- }
- } while (group = group->next, group != sd->groups);
-
- if (!idlest || 100*this_load < imbalance*min_load)
- return NULL;
- return idlest;
-}
-
-/*
- * find_idlest_cpu - find the idlest cpu among the cpus in group.
- */
-static int
-find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
-{
- unsigned long load, min_load = ULONG_MAX;
- int idlest = -1;
- int i;
-
- /* Traverse only the allowed CPUs */
- for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) {
- load = weighted_cpuload(i);
-
- if (load < min_load || (load == min_load && i == this_cpu)) {
- min_load = load;
- idlest = i;
- }
- }
-
- return idlest;
-}
-
-/*
- * sched_balance_self: balance the current task (running on cpu) in domains
- * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
- * SD_BALANCE_EXEC.
- *
- * Balance, ie. select the least loaded group.
- *
- * Returns the target CPU number, or the same CPU if no balancing is needed.
- *
- * preempt must be disabled.
- */
-static int sched_balance_self(int cpu, int flag)
-{
- struct task_struct *t = current;
- struct sched_domain *tmp, *sd = NULL;
-
- for_each_domain(cpu, tmp) {
- /*
- * If power savings logic is enabled for a domain, stop there.
- */
- if (tmp->flags & SD_POWERSAVINGS_BALANCE)
- break;
- if (tmp->flags & flag)
- sd = tmp;
- }
-
- if (sd)
- update_shares(sd);
-
- while (sd) {
- struct sched_group *group;
- int new_cpu, weight;
-
- if (!(sd->flags & flag)) {
- sd = sd->child;
- continue;
- }
-
- group = find_idlest_group(sd, t, cpu);
- if (!group) {
- sd = sd->child;
- continue;
- }
-
- new_cpu = find_idlest_cpu(group, t, cpu);
- if (new_cpu == -1 || new_cpu == cpu) {
- /* Now try balancing at a lower domain level of cpu */
- sd = sd->child;
- continue;
- }
-
- /* Now try balancing at a lower domain level of new_cpu */
- cpu = new_cpu;
- weight = cpumask_weight(sched_domain_span(sd));
- sd = NULL;
- for_each_domain(cpu, tmp) {
- if (weight <= cpumask_weight(sched_domain_span(tmp)))
- break;
- if (tmp->flags & flag)
- sd = tmp;
- }
- /* while loop will break here if sd == NULL */
- }
-
- return cpu;
-}
-
#endif /* CONFIG_SMP */
/**
@@ -2455,37 +2312,22 @@ void task_oncpu_function_call(struct task_struct *p,
*
* returns failure only if the task is already active.
*/
-static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
+static int try_to_wake_up(struct task_struct *p, unsigned int state,
+ int wake_flags)
{
int cpu, orig_cpu, this_cpu, success = 0;
unsigned long flags;
- long old_state;
struct rq *rq;
if (!sched_feat(SYNC_WAKEUPS))
- sync = 0;
-
-#ifdef CONFIG_SMP
- if (sched_feat(LB_WAKEUP_UPDATE) && !root_task_group_empty()) {
- struct sched_domain *sd;
+ wake_flags &= ~WF_SYNC;
- this_cpu = raw_smp_processor_id();
- cpu = task_cpu(p);
-
- for_each_domain(this_cpu, sd) {
- if (cpumask_test_cpu(cpu, sched_domain_span(sd))) {
- update_shares(sd);
- break;
- }
- }
- }
-#endif
+ this_cpu = get_cpu();
smp_wmb();
rq = task_rq_lock(p, &flags);
update_rq_clock(rq);
- old_state = p->state;
- if (!(old_state & state))
+ if (!(p->state & state))
goto out;
if (p->se.on_rq)
@@ -2493,27 +2335,29 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
cpu = task_cpu(p);
orig_cpu = cpu;
- this_cpu = smp_processor_id();
#ifdef CONFIG_SMP
if (unlikely(task_running(rq, p)))
goto out_activate;
- cpu = p->sched_class->select_task_rq(p, sync);
- if (cpu != orig_cpu) {
+ /*
+ * In order to handle concurrent wakeups and release the rq->lock
+ * we put the task in TASK_WAKING state.
+ *
+ * First fix up the nr_uninterruptible count:
+ */
+ if (task_contributes_to_load(p))
+ rq->nr_uninterruptible--;
+ p->state = TASK_WAKING;
+ task_rq_unlock(rq, &flags);
+
+ cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
+ if (cpu != orig_cpu)
set_task_cpu(p, cpu);
- task_rq_unlock(rq, &flags);
- /* might preempt at this point */
- rq = task_rq_lock(p, &flags);
- old_state = p->state;
- if (!(old_state & state))
- goto out;
- if (p->se.on_rq)
- goto out_running;
- this_cpu = smp_processor_id();
- cpu = task_cpu(p);
- }
+ rq = task_rq_lock(p, &flags);
+ WARN_ON(p->state != TASK_WAKING);
+ cpu = task_cpu(p);
#ifdef CONFIG_SCHEDSTATS
schedstat_inc(rq, ttwu_count);
@@ -2533,7 +2377,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
out_activate:
#endif /* CONFIG_SMP */
schedstat_inc(p, se.nr_wakeups);
- if (sync)
+ if (wake_flags & WF_SYNC)
schedstat_inc(p, se.nr_wakeups_sync);
if (orig_cpu != cpu)
schedstat_inc(p, se.nr_wakeups_migrate);
@@ -2562,7 +2406,7 @@ out_activate:
out_running:
trace_sched_wakeup(rq, p, success);
- check_preempt_curr(rq, p, sync);
+ check_preempt_curr(rq, p, wake_flags);
p->state = TASK_RUNNING;
#ifdef CONFIG_SMP
@@ -2571,6 +2415,7 @@ out_running:
#endif
out:
task_rq_unlock(rq, &flags);
+ put_cpu();
return success;
}
@@ -2613,6 +2458,7 @@ static void __sched_fork(struct task_struct *p)
p->se.avg_overlap = 0;
p->se.start_runtime = 0;
p->se.avg_wakeup = sysctl_sched_wakeup_granularity;
+ p->se.avg_running = 0;
#ifdef CONFIG_SCHEDSTATS
p->se.wait_start = 0;
@@ -2674,11 +2520,6 @@ void sched_fork(struct task_struct *p, int clone_flags)
__sched_fork(p);
-#ifdef CONFIG_SMP
- cpu = sched_balance_self(cpu, SD_BALANCE_FORK);
-#endif
- set_task_cpu(p, cpu);
-
/*
* Make sure we do not leak PI boosting priority to the child.
*/
@@ -2709,6 +2550,11 @@ void sched_fork(struct task_struct *p, int clone_flags)
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
+#ifdef CONFIG_SMP
+ cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0);
+#endif
+ set_task_cpu(p, cpu);
+
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on()))
memset(&p->sched_info, 0, sizeof(p->sched_info));
@@ -2754,7 +2600,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
inc_nr_running(rq);
}
trace_sched_wakeup_new(rq, p, 1);
- check_preempt_curr(rq, p, 0);
+ check_preempt_curr(rq, p, WF_FORK);
#ifdef CONFIG_SMP
if (p->sched_class->task_wake_up)
p->sched_class->task_wake_up(rq, p);
@@ -3263,7 +3109,7 @@ out:
void sched_exec(void)
{
int new_cpu, this_cpu = get_cpu();
- new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC);
+ new_cpu = current->sched_class->select_task_rq(current, SD_BALANCE_EXEC, 0);
put_cpu();
if (new_cpu != this_cpu)
sched_migrate_task(current, new_cpu);
@@ -3683,11 +3529,6 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
*imbalance = sds->min_load_per_task;
sds->busiest = sds->group_min;
- if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) {
- cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu =
- group_first_cpu(sds->group_leader);
- }
-
return 1;
}
@@ -3711,7 +3552,18 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
}
#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
-unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu)
+
+unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
+{
+ return SCHED_LOAD_SCALE;
+}
+
+unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu)
+{
+ return default_scale_freq_power(sd, cpu);
+}
+
+unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
{
unsigned long weight = cpumask_weight(sched_domain_span(sd));
unsigned long smt_gain = sd->smt_gain;
@@ -3721,6 +3573,11 @@ unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu)
return smt_gain;
}
+unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu)
+{
+ return default_scale_smt_power(sd, cpu);
+}
+
unsigned long scale_rt_power(int cpu)
{
struct rq *rq = cpu_rq(cpu);
@@ -3745,10 +3602,19 @@ static void update_cpu_power(struct sched_domain *sd, int cpu)
unsigned long power = SCHED_LOAD_SCALE;
struct sched_group *sdg = sd->groups;
- /* here we could scale based on cpufreq */
+ if (sched_feat(ARCH_POWER))
+ power *= arch_scale_freq_power(sd, cpu);
+ else
+ power *= default_scale_freq_power(sd, cpu);
+
+ power >>= SCHED_LOAD_SHIFT;
if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
- power *= arch_scale_smt_power(sd, cpu);
+ if (sched_feat(ARCH_POWER))
+ power *= arch_scale_smt_power(sd, cpu);
+ else
+ power *= default_scale_smt_power(sd, cpu);
+
power >>= SCHED_LOAD_SHIFT;
}
@@ -4161,26 +4027,6 @@ ret:
return NULL;
}
-static struct sched_group *group_of(int cpu)
-{
- struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd);
-
- if (!sd)
- return NULL;
-
- return sd->groups;
-}
-
-static unsigned long power_of(int cpu)
-{
- struct sched_group *group = group_of(cpu);
-
- if (!group)
- return SCHED_LOAD_SCALE;
-
- return group->cpu_power;
-}
-
/*
* find_busiest_queue - find the busiest runqueue among the cpus in group.
*/
@@ -5465,14 +5311,13 @@ static inline void schedule_debug(struct task_struct *prev)
#endif
}
-static void put_prev_task(struct rq *rq, struct task_struct *prev)
+static void put_prev_task(struct rq *rq, struct task_struct *p)
{
- if (prev->state == TASK_RUNNING) {
- u64 runtime = prev->se.sum_exec_runtime;
+ u64 runtime = p->se.sum_exec_runtime - p->se.prev_sum_exec_runtime;
- runtime -= prev->se.prev_sum_exec_runtime;
- runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
+ update_avg(&p->se.avg_running, runtime);
+ if (p->state == TASK_RUNNING) {
/*
* In order to avoid avg_overlap growing stale when we are
* indeed overlapping and hence not getting put to sleep, grow
@@ -5482,9 +5327,12 @@ static void put_prev_task(struct rq *rq, struct task_struct *prev)
* correlates to the amount of cache footprint a task can
* build up.
*/
- update_avg(&prev->se.avg_overlap, runtime);
+ runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
+ update_avg(&p->se.avg_overlap, runtime);
+ } else {
+ update_avg(&p->se.avg_running, 0);
}
- prev->sched_class->put_prev_task(rq, prev);
+ p->sched_class->put_prev_task(rq, p);
}
/*
@@ -5716,10 +5564,10 @@ asmlinkage void __sched preempt_schedule_irq(void)
#endif /* CONFIG_PREEMPT */
-int default_wake_function(wait_queue_t *curr, unsigned mode, int sync,
+int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
void *key)
{
- return try_to_wake_up(curr->private, mode, sync);
+ return try_to_wake_up(curr->private, mode, wake_flags);
}
EXPORT_SYMBOL(default_wake_function);
@@ -5733,14 +5581,14 @@ EXPORT_SYMBOL(default_wake_function);
* zero in this (rare) case, and we handle it by continuing to scan the queue.
*/
static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
- int nr_exclusive, int sync, void *key)
+ int nr_exclusive, int wake_flags, void *key)
{
wait_queue_t *curr, *next;
list_for_each_entry_safe(curr, next, &q->task_list, task_list) {
unsigned flags = curr->flags;
- if (curr->func(curr, mode, sync, key) &&
+ if (curr->func(curr, mode, wake_flags, key) &&
(flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
break;
}
@@ -5801,16 +5649,16 @@ void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, void *key)
{
unsigned long flags;
- int sync = 1;
+ int wake_flags = WF_SYNC;
if (unlikely(!q))
return;
if (unlikely(!nr_exclusive))
- sync = 0;
+ wake_flags = 0;
spin_lock_irqsave(&q->lock, flags);
- __wake_up_common(q, mode, nr_exclusive, sync, key);
+ __wake_up_common(q, mode, nr_exclusive, wake_flags, key);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL_GPL(__wake_up_sync_key);
@@ -8000,9 +7848,7 @@ static int sd_degenerate(struct sched_domain *sd)
}
/* Following flags don't use groups */
- if (sd->flags & (SD_WAKE_IDLE |
- SD_WAKE_AFFINE |
- SD_WAKE_BALANCE))
+ if (sd->flags & (SD_WAKE_AFFINE))
return 0;
return 1;
@@ -8019,10 +7865,6 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent)))
return 0;
- /* Does parent contain flags not in child? */
- /* WAKE_BALANCE is a subset of WAKE_AFFINE */
- if (cflags & SD_WAKE_AFFINE)
- pflags &= ~SD_WAKE_BALANCE;
/* Flags needing groups don't count if only 1 group in parent */
if (parent->groups == parent->groups->next) {
pflags &= ~(SD_LOAD_BALANCE |
@@ -8708,10 +8550,10 @@ static void set_domain_attribute(struct sched_domain *sd,
request = attr->relax_domain_level;
if (request < sd->level) {
/* turn off idle balance on this domain */
- sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE);
+ sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
} else {
/* turn on idle balance on this domain */
- sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE);
+ sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
}
}
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 5ddbd0891267..efb84409bc43 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -395,6 +395,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
PN(se.sum_exec_runtime);
PN(se.avg_overlap);
PN(se.avg_wakeup);
+ PN(se.avg_running);
nr_switches = p->nvcsw + p->nivcsw;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index aa7f84121016..10d218ab69f2 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -711,7 +711,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
if (!initial) {
/* sleeps upto a single latency don't count. */
- if (sched_feat(NEW_FAIR_SLEEPERS)) {
+ if (sched_feat(FAIR_SLEEPERS)) {
unsigned long thresh = sysctl_sched_latency;
/*
@@ -725,6 +725,13 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
task_of(se)->policy != SCHED_IDLE))
thresh = calc_delta_fair(thresh, se);
+ /*
+ * Halve their sleep time's effect, to allow
+ * for a gentler effect of sleepers:
+ */
+ if (sched_feat(GENTLE_FAIR_SLEEPERS))
+ thresh >>= 1;
+
vruntime -= thresh;
}
}
@@ -757,10 +764,10 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
static void __clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- if (cfs_rq->last == se)
+ if (!se || cfs_rq->last == se)
cfs_rq->last = NULL;
- if (cfs_rq->next == se)
+ if (!se || cfs_rq->next == se)
cfs_rq->next = NULL;
}
@@ -1062,83 +1069,6 @@ static void yield_task_fair(struct rq *rq)
se->vruntime = rightmost->vruntime + 1;
}
-/*
- * wake_idle() will wake a task on an idle cpu if task->cpu is
- * not idle and an idle cpu is available. The span of cpus to
- * search starts with cpus closest then further out as needed,
- * so we always favor a closer, idle cpu.
- * Domains may include CPUs that are not usable for migration,
- * hence we need to mask them out (rq->rd->online)
- *
- * Returns the CPU we should wake onto.
- */
-#if defined(ARCH_HAS_SCHED_WAKE_IDLE)
-
-#define cpu_rd_active(cpu, rq) cpumask_test_cpu(cpu, rq->rd->online)
-
-static int wake_idle(int cpu, struct task_struct *p)
-{
- struct sched_domain *sd;
- int i;
- unsigned int chosen_wakeup_cpu;
- int this_cpu;
- struct rq *task_rq = task_rq(p);
-
- /*
- * At POWERSAVINGS_BALANCE_WAKEUP level, if both this_cpu and prev_cpu
- * are idle and this is not a kernel thread and this task's affinity
- * allows it to be moved to preferred cpu, then just move!
- */
-
- this_cpu = smp_processor_id();
- chosen_wakeup_cpu =
- cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu;
-
- if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP &&
- idle_cpu(cpu) && idle_cpu(this_cpu) &&
- p->mm && !(p->flags & PF_KTHREAD) &&
- cpu_isset(chosen_wakeup_cpu, p->cpus_allowed))
- return chosen_wakeup_cpu;
-
- /*
- * If it is idle, then it is the best cpu to run this task.
- *
- * This cpu is also the best, if it has more than one task already.
- * Siblings must be also busy(in most cases) as they didn't already
- * pickup the extra load from this cpu and hence we need not check
- * sibling runqueue info. This will avoid the checks and cache miss
- * penalities associated with that.
- */
- if (idle_cpu(cpu) || cpu_rq(cpu)->cfs.nr_running > 1)
- return cpu;
-
- for_each_domain(cpu, sd) {
- if ((sd->flags & SD_WAKE_IDLE)
- || ((sd->flags & SD_WAKE_IDLE_FAR)
- && !task_hot(p, task_rq->clock, sd))) {
- for_each_cpu_and(i, sched_domain_span(sd),
- &p->cpus_allowed) {
- if (cpu_rd_active(i, task_rq) && idle_cpu(i)) {
- if (i != task_cpu(p)) {
- schedstat_inc(p,
- se.nr_wakeups_idle);
- }
- return i;
- }
- }
- } else {
- break;
- }
- }
- return cpu;
-}
-#else /* !ARCH_HAS_SCHED_WAKE_IDLE*/
-static inline int wake_idle(int cpu, struct task_struct *p)
-{
- return cpu;
-}
-#endif
-
#ifdef CONFIG_SMP
#ifdef CONFIG_FAIR_GROUP_SCHED
@@ -1225,25 +1155,34 @@ static inline unsigned long effective_load(struct task_group *tg, int cpu,
#endif
-static int
-wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
- struct task_struct *p, int prev_cpu, int this_cpu, int sync,
- int idx, unsigned long load, unsigned long this_load,
- unsigned int imbalance)
+static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
{
- struct task_struct *curr = this_rq->curr;
- struct task_group *tg;
- unsigned long tl = this_load;
+ struct task_struct *curr = current;
+ unsigned long this_load, load;
+ int idx, this_cpu, prev_cpu;
unsigned long tl_per_task;
+ unsigned int imbalance;
+ struct task_group *tg;
unsigned long weight;
int balanced;
- if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS))
- return 0;
+ idx = sd->wake_idx;
+ this_cpu = smp_processor_id();
+ prev_cpu = task_cpu(p);
+ load = source_load(prev_cpu, idx);
+ this_load = target_load(this_cpu, idx);
- if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost ||
- p->se.avg_overlap > sysctl_sched_migration_cost))
- sync = 0;
+ if (sync) {
+ if (sched_feat(SYNC_LESS) &&
+ (curr->se.avg_overlap > sysctl_sched_migration_cost ||
+ p->se.avg_overlap > sysctl_sched_migration_cost))
+ sync = 0;
+ } else {
+ if (sched_feat(SYNC_MORE) &&
+ (curr->se.avg_overlap < sysctl_sched_migration_cost &&
+ p->se.avg_overlap < sysctl_sched_migration_cost))
+ sync = 1;
+ }
/*
* If sync wakeup then subtract the (maximum possible)
@@ -1254,24 +1193,26 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
tg = task_group(current);
weight = current->se.load.weight;
- tl += effective_load(tg, this_cpu, -weight, -weight);
+ this_load += effective_load(tg, this_cpu, -weight, -weight);
load += effective_load(tg, prev_cpu, 0, -weight);
}
tg = task_group(p);
weight = p->se.load.weight;
+ imbalance = 100 + (sd->imbalance_pct - 100) / 2;
+
/*
* In low-load situations, where prev_cpu is idle and this_cpu is idle
- * due to the sync cause above having dropped tl to 0, we'll always have
- * an imbalance, but there's really nothing you can do about that, so
- * that's good too.
+ * due to the sync cause above having dropped this_load to 0, we'll
+ * always have an imbalance, but there's really nothing you can do
+ * about that, so that's good too.
*
* Otherwise check if either cpus are near enough in load to allow this
* task to be woken on this_cpu.
*/
- balanced = !tl ||
- 100*(tl + effective_load(tg, this_cpu, weight, weight)) <=
+ balanced = !this_load ||
+ 100*(this_load + effective_load(tg, this_cpu, weight, weight)) <=
imbalance*(load + effective_load(tg, prev_cpu, 0, weight));
/*
@@ -1285,14 +1226,15 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
schedstat_inc(p, se.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);
- if (balanced || (tl <= load && tl + target_load(prev_cpu, idx) <=
- tl_per_task)) {
+ if (balanced ||
+ (this_load <= load &&
+ this_load + target_load(prev_cpu, idx) <= tl_per_task)) {
/*
* This domain has SD_WAKE_AFFINE and
* p is cache cold in this domain, and
* there is no bad imbalance.
*/
- schedstat_inc(this_sd, ttwu_move_affine);
+ schedstat_inc(sd, ttwu_move_affine);
schedstat_inc(p, se.nr_wakeups_affine);
return 1;
@@ -1300,65 +1242,215 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
return 0;
}
-static int select_task_rq_fair(struct task_struct *p, int sync)
+/*
+ * find_idlest_group finds and returns the least busy CPU group within the
+ * domain.
+ */
+static struct sched_group *
+find_idlest_group(struct sched_domain *sd, struct task_struct *p,
+ int this_cpu, int load_idx)
{
- struct sched_domain *sd, *this_sd = NULL;
- int prev_cpu, this_cpu, new_cpu;
- unsigned long load, this_load;
- struct rq *this_rq;
- unsigned int imbalance;
- int idx;
+ struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups;
+ unsigned long min_load = ULONG_MAX, this_load = 0;
+ int imbalance = 100 + (sd->imbalance_pct-100)/2;
- prev_cpu = task_cpu(p);
- this_cpu = smp_processor_id();
- this_rq = cpu_rq(this_cpu);
- new_cpu = prev_cpu;
+ do {
+ unsigned long load, avg_load;
+ int local_group;
+ int i;
- /*
- * 'this_sd' is the first domain that both
- * this_cpu and prev_cpu are present in:
- */
- for_each_domain(this_cpu, sd) {
- if (cpumask_test_cpu(prev_cpu, sched_domain_span(sd))) {
- this_sd = sd;
- break;
+ /* Skip over this group if it has no CPUs allowed */
+ if (!cpumask_intersects(sched_group_cpus(group),
+ &p->cpus_allowed))
+ continue;
+
+ local_group = cpumask_test_cpu(this_cpu,
+ sched_group_cpus(group));
+
+ /* Tally up the load of all CPUs in the group */
+ avg_load = 0;
+
+ for_each_cpu(i, sched_group_cpus(group)) {
+ /* Bias balancing toward cpus of our domain */
+ if (local_group)
+ load = source_load(i, load_idx);
+ else
+ load = target_load(i, load_idx);
+
+ avg_load += load;
+ }
+
+ /* Adjust by relative CPU power of the group */
+ avg_load = (avg_load * SCHED_LOAD_SCALE) / group->cpu_power;
+
+ if (local_group) {
+ this_load = avg_load;
+ this = group;
+ } else if (avg_load < min_load) {
+ min_load = avg_load;
+ idlest = group;
+ }
+ } while (group = group->next, group != sd->groups);
+
+ if (!idlest || 100*this_load < imbalance*min_load)
+ return NULL;
+ return idlest;
+}
+
+/*
+ * find_idlest_cpu - find the idlest cpu among the cpus in group.
+ */
+static int
+find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
+{
+ unsigned long load, min_load = ULONG_MAX;
+ int idlest = -1;
+ int i;
+
+ /* Traverse only the allowed CPUs */
+ for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) {
+ load = weighted_cpuload(i);
+
+ if (load < min_load || (load == min_load && i == this_cpu)) {
+ min_load = load;
+ idlest = i;
}
}
- if (unlikely(!cpumask_test_cpu(this_cpu, &p->cpus_allowed)))
- goto out;
+ return idlest;
+}
- /*
- * Check for affine wakeup and passive balancing possibilities.
- */
- if (!this_sd)
+/*
+ * sched_balance_self: balance the current task (running on cpu) in domains
+ * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
+ * SD_BALANCE_EXEC.
+ *
+ * Balance, ie. select the least loaded group.
+ *
+ * Returns the target CPU number, or the same CPU if no balancing is needed.
+ *
+ * preempt must be disabled.
+ */
+static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
+{
+ struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL;
+ int cpu = smp_processor_id();
+ int prev_cpu = task_cpu(p);
+ int new_cpu = cpu;
+ int want_affine = 0;
+ int want_sd = 1;
+ int sync = wake_flags & WF_SYNC;
+
+ if (sd_flag & SD_BALANCE_WAKE) {
+ if (sched_feat(AFFINE_WAKEUPS))
+ want_affine = 1;
+ new_cpu = prev_cpu;
+ }
+
+ rcu_read_lock();
+ for_each_domain(cpu, tmp) {
+ /*
+ * If power savings logic is enabled for a domain, see if we
+ * are not overloaded, if so, don't balance wider.
+ */
+ if (tmp->flags & (SD_POWERSAVINGS_BALANCE|SD_PREFER_LOCAL)) {
+ unsigned long power = 0;
+ unsigned long nr_running = 0;
+ unsigned long capacity;
+ int i;
+
+ for_each_cpu(i, sched_domain_span(tmp)) {
+ power += power_of(i);
+ nr_running += cpu_rq(i)->cfs.nr_running;
+ }
+
+ capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE);
+
+ if (tmp->flags & SD_POWERSAVINGS_BALANCE)
+ nr_running /= 2;
+
+ if (nr_running < capacity)
+ want_sd = 0;
+ }
+
+ if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
+ cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
+
+ affine_sd = tmp;
+ want_affine = 0;
+ }
+
+ if (!want_sd && !want_affine)
+ break;
+
+ if (!(tmp->flags & sd_flag))
+ continue;
+
+ if (want_sd)
+ sd = tmp;
+ }
+
+ if (sched_feat(LB_SHARES_UPDATE)) {
+ /*
+ * Pick the largest domain to update shares over
+ */
+ tmp = sd;
+ if (affine_sd && (!tmp ||
+ cpumask_weight(sched_domain_span(affine_sd)) >
+ cpumask_weight(sched_domain_span(sd))))
+ tmp = affine_sd;
+
+ if (tmp)
+ update_shares(tmp);
+ }
+
+ if (affine_sd && wake_affine(affine_sd, p, sync)) {
+ new_cpu = cpu;
goto out;
+ }
- idx = this_sd->wake_idx;
+ while (sd) {
+ int load_idx = sd->forkexec_idx;
+ struct sched_group *group;
+ int weight;
- imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
+ if (!(sd->flags & sd_flag)) {
+ sd = sd->child;
+ continue;
+ }
- load = source_load(prev_cpu, idx);
- this_load = target_load(this_cpu, idx);
+ if (sd_flag & SD_BALANCE_WAKE)
+ load_idx = sd->wake_idx;
- if (wake_affine(this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx,
- load, this_load, imbalance))
- return this_cpu;
+ group = find_idlest_group(sd, p, cpu, load_idx);
+ if (!group) {
+ sd = sd->child;
+ continue;
+ }
- /*
- * Start passive balancing when half the imbalance_pct
- * limit is reached.
- */
- if (this_sd->flags & SD_WAKE_BALANCE) {
- if (imbalance*this_load <= 100*load) {
- schedstat_inc(this_sd, ttwu_move_balance);
- schedstat_inc(p, se.nr_wakeups_passive);
- return this_cpu;
+ new_cpu = find_idlest_cpu(group, p, cpu);
+ if (new_cpu == -1 || new_cpu == cpu) {
+ /* Now try balancing at a lower domain level of cpu */
+ sd = sd->child;
+ continue;
}
+
+ /* Now try balancing at a lower domain level of new_cpu */
+ cpu = new_cpu;
+ weight = cpumask_weight(sched_domain_span(sd));
+ sd = NULL;
+ for_each_domain(cpu, tmp) {
+ if (weight <= cpumask_weight(sched_domain_span(tmp)))
+ break;
+ if (tmp->flags & sd_flag)
+ sd = tmp;
+ }
+ /* while loop will break here if sd == NULL */
}
out:
- return wake_idle(new_cpu, p);
+ rcu_read_unlock();
+ return new_cpu;
}
#endif /* CONFIG_SMP */
@@ -1471,11 +1563,12 @@ static void set_next_buddy(struct sched_entity *se)
/*
* Preempt the current task with a newly woken task if needed:
*/
-static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync)
+static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
{
struct task_struct *curr = rq->curr;
struct sched_entity *se = &curr->se, *pse = &p->se;
struct cfs_rq *cfs_rq = task_cfs_rq(curr);
+ int sync = wake_flags & WF_SYNC;
update_curr(cfs_rq);
@@ -1501,7 +1594,8 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync)
*/
if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle))
set_last_buddy(se);
- set_next_buddy(pse);
+ if (sched_feat(NEXT_BUDDY) && !(wake_flags & WF_FORK))
+ set_next_buddy(pse);
/*
* We can come here with TIF_NEED_RESCHED already set from new task
@@ -1523,16 +1617,25 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync)
return;
}
- if (!sched_feat(WAKEUP_PREEMPT))
- return;
-
- if (sched_feat(WAKEUP_OVERLAP) && (sync ||
- (se->avg_overlap < sysctl_sched_migration_cost &&
- pse->avg_overlap < sysctl_sched_migration_cost))) {
+ if ((sched_feat(WAKEUP_SYNC) && sync) ||
+ (sched_feat(WAKEUP_OVERLAP) &&
+ (se->avg_overlap < sysctl_sched_migration_cost &&
+ pse->avg_overlap < sysctl_sched_migration_cost))) {
resched_task(curr);
return;
}
+ if (sched_feat(WAKEUP_RUNNING)) {
+ if (pse->avg_running < se->avg_running) {
+ set_next_buddy(pse);
+ resched_task(curr);
+ return;
+ }
+ }
+
+ if (!sched_feat(WAKEUP_PREEMPT))
+ return;
+
find_matching_se(&se, &pse);
BUG_ON(!pse);
@@ -1555,8 +1658,13 @@ static struct task_struct *pick_next_task_fair(struct rq *rq)
/*
* If se was a buddy, clear it so that it will have to earn
* the favour again.
+ *
+ * If se was not a buddy, clear the buddies because neither
+ * was elegible to run, let them earn it again.
+ *
+ * IOW. unconditionally clear buddies.
*/
- __clear_buddies(cfs_rq, se);
+ __clear_buddies(cfs_rq, NULL);
set_next_entity(cfs_rq, se);
cfs_rq = group_cfs_rq(se);
} while (cfs_rq);
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index e2dc63a5815d..0d94083582c7 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -1,17 +1,123 @@
-SCHED_FEAT(NEW_FAIR_SLEEPERS, 0)
+/*
+ * Disregards a certain amount of sleep time (sched_latency_ns) and
+ * considers the task to be running during that period. This gives it
+ * a service deficit on wakeup, allowing it to run sooner.
+ */
+SCHED_FEAT(FAIR_SLEEPERS, 1)
+
+/*
+ * Only give sleepers 50% of their service deficit. This allows
+ * them to run sooner, but does not allow tons of sleepers to
+ * rip the spread apart.
+ */
+SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1)
+
+/*
+ * By not normalizing the sleep time, heavy tasks get an effective
+ * longer period, and lighter task an effective shorter period they
+ * are considered running.
+ */
SCHED_FEAT(NORMALIZED_SLEEPER, 0)
-SCHED_FEAT(ADAPTIVE_GRAN, 1)
-SCHED_FEAT(WAKEUP_PREEMPT, 1)
+
+/*
+ * Place new tasks ahead so that they do not starve already running
+ * tasks
+ */
SCHED_FEAT(START_DEBIT, 1)
+
+/*
+ * Should wakeups try to preempt running tasks.
+ */
+SCHED_FEAT(WAKEUP_PREEMPT, 1)
+
+/*
+ * Compute wakeup_gran based on task behaviour, clipped to
+ * [0, sched_wakeup_gran_ns]
+ */
+SCHED_FEAT(ADAPTIVE_GRAN, 1)
+
+/*
+ * When converting the wakeup granularity to virtual time, do it such
+ * that heavier tasks preempting a lighter task have an edge.
+ */
+SCHED_FEAT(ASYM_GRAN, 1)
+
+/*
+ * Always wakeup-preempt SYNC wakeups, see SYNC_WAKEUPS.
+ */
+SCHED_FEAT(WAKEUP_SYNC, 0)
+
+/*
+ * Wakeup preempt based on task behaviour. Tasks that do not overlap
+ * don't get preempted.
+ */
+SCHED_FEAT(WAKEUP_OVERLAP, 0)
+
+/*
+ * Wakeup preemption towards tasks that run short
+ */
+SCHED_FEAT(WAKEUP_RUNNING, 0)
+
+/*
+ * Use the SYNC wakeup hint, pipes and the likes use this to indicate
+ * the remote end is likely to consume the data we just wrote, and
+ * therefore has cache benefit from being placed on the same cpu, see
+ * also AFFINE_WAKEUPS.
+ */
+SCHED_FEAT(SYNC_WAKEUPS, 1)
+
+/*
+ * Based on load and program behaviour, see if it makes sense to place
+ * a newly woken task on the same cpu as the task that woke it --
+ * improve cache locality. Typically used with SYNC wakeups as
+ * generated by pipes and the like, see also SYNC_WAKEUPS.
+ */
SCHED_FEAT(AFFINE_WAKEUPS, 1)
+
+/*
+ * Weaken SYNC hint based on overlap
+ */
+SCHED_FEAT(SYNC_LESS, 1)
+
+/*
+ * Add SYNC hint based on overlap
+ */
+SCHED_FEAT(SYNC_MORE, 0)
+
+/*
+ * Prefer to schedule the task we woke last (assuming it failed
+ * wakeup-preemption), since its likely going to consume data we
+ * touched, increases cache locality.
+ */
+SCHED_FEAT(NEXT_BUDDY, 0)
+
+/*
+ * Prefer to schedule the task that ran last (when we did
+ * wake-preempt) as that likely will touch the same data, increases
+ * cache locality.
+ */
+SCHED_FEAT(LAST_BUDDY, 1)
+
+/*
+ * Consider buddies to be cache hot, decreases the likelyness of a
+ * cache buddy being migrated away, increases cache locality.
+ */
SCHED_FEAT(CACHE_HOT_BUDDY, 1)
-SCHED_FEAT(SYNC_WAKEUPS, 1)
+
+/*
+ * Use arch dependent cpu power functions
+ */
+SCHED_FEAT(ARCH_POWER, 0)
+
SCHED_FEAT(HRTICK, 0)
SCHED_FEAT(DOUBLE_TICK, 0)
-SCHED_FEAT(ASYM_GRAN, 1)
SCHED_FEAT(LB_BIAS, 1)
-SCHED_FEAT(LB_WAKEUP_UPDATE, 1)
+SCHED_FEAT(LB_SHARES_UPDATE, 1)
SCHED_FEAT(ASYM_EFF_LOAD, 1)
-SCHED_FEAT(WAKEUP_OVERLAP, 0)
-SCHED_FEAT(LAST_BUDDY, 1)
+
+/*
+ * Spin-wait on mutex acquisition when the mutex owner is running on
+ * another cpu -- assumes that when the owner is running, it will soon
+ * release the lock. Decreases scheduling overhead.
+ */
SCHED_FEAT(OWNER_SPIN, 1)
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index 499672c10cbd..a8b448af004b 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -6,7 +6,7 @@
*/
#ifdef CONFIG_SMP
-static int select_task_rq_idle(struct task_struct *p, int sync)
+static int select_task_rq_idle(struct task_struct *p, int sd_flag, int flags)
{
return task_cpu(p); /* IDLE tasks as never migrated */
}
@@ -14,7 +14,7 @@ static int select_task_rq_idle(struct task_struct *p, int sync)
/*
* Idle tasks are unconditionally rescheduled:
*/
-static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int sync)
+static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags)
{
resched_task(rq->idle);
}
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 2eb4bd6a526c..13de7126a6ab 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -938,10 +938,13 @@ static void yield_task_rt(struct rq *rq)
#ifdef CONFIG_SMP
static int find_lowest_rq(struct task_struct *task);
-static int select_task_rq_rt(struct task_struct *p, int sync)
+static int select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)
{
struct rq *rq = task_rq(p);
+ if (sd_flag != SD_BALANCE_WAKE)
+ return smp_processor_id();
+
/*
* If the current task is an RT task, then
* try to see if we can wake this RT task up on another
@@ -999,7 +1002,7 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
/*
* Preempt the current task with a newly woken task if needed:
*/
-static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync)
+static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags)
{
if (p->prio < rq->curr->prio) {
resched_task(rq->curr);