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scheduler_affine: Put small tasks on a single core

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This commit is contained in:
Pawel Dziepak 2013-10-23 01:58:49 +02:00
parent 4c4994435d
commit 2df11d8a80
1 changed files with 32 additions and 15 deletions
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47
src/system/kernel/scheduler/scheduler_affine.cpp
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@ -51,10 +51,11 @@ const bigtime_t kMaxThreadQuantum = 10000;
const bigtime_t kCacheExpire = 100000;
static bigtime_t sDisableSmallTaskPacking;
static int32 sSmallTaskCore = -1;
static scheduler_mode sSchedulerMode;
static int32 (*sChooseCore)(int32 priority);
static int32 (*sChooseCore)(Thread* thread);
// Heaps in sCPUPriorityHeaps are used for load balancing on a core the logical
@ -511,10 +512,12 @@ affine_update_thread_heaps(int32 core)
if (newKey > thread_max_threads()) {
if (oldKey <= thread_max_threads()) {
if (sSmallTaskCore == entry->fCoreID)
sSmallTaskCore = -1;
sCoreThreadHeap->ModifyKey(entry, -1);
ASSERT(sCoreThreadHeap->PeekMinimum() == entry);
sCoreThreadHeap->RemoveMinimum();
ASSERT(sCoreThreadHeap->PeekMinimum() != entry);
sCoreCPUBoundThreadHeap->Insert(entry, newKey);
} else
@ -656,7 +659,7 @@ affine_update_priority_heaps(int32 cpu, int32 priority)
static int32
affine_choose_core_performance(int32 priority)
affine_choose_core_performance(Thread* thread)
{
CoreEntry* entry;
@ -671,6 +674,8 @@ affine_choose_core_performance(int32 priority)
} else {
// no idle cores, use least occupied core
entry = sCorePriorityHeap->PeekRoot();
int32 priority = affine_get_effective_priority(thread);
if (AffineCorePriorityHeap::GetKey(entry) >= priority) {
entry = sCoreThreadHeap->PeekMinimum();
if (entry == NULL)
@ -684,17 +689,24 @@ affine_choose_core_performance(int32 priority)
static int32
affine_choose_core_power_saving(int32 priority)
affine_choose_core_power_saving(Thread* thread)
{
CoreEntry* entry;
entry = sCorePriorityHeap->PeekRoot();
if (entry != NULL && AffineCorePriorityHeap::GetKey(entry) < priority) {
// run immediately on already woken core
} else if (sDisableSmallTaskPacking < system_time()
int32 priority = affine_get_effective_priority(thread);
int32 penalty = thread->scheduler_data->priority_penalty;
if (!sDisableSmallTaskPacking && penalty == 0
&& sCoreThreadHeap->PeekMaximum() != NULL) {
// try to pack all threads on one core
entry = sCoreThreadHeap->PeekMaximum();
if (sSmallTaskCore < 0)
sSmallTaskCore = sCoreThreadHeap->PeekMaximum()->fCoreID;
entry = &sCoreEntries[sSmallTaskCore];
} else if (sCorePriorityHeap->PeekRoot() != NULL
&& AffineCorePriorityHeap::GetKey(sCorePriorityHeap->PeekRoot())
< priority) {
// run immediately on already woken core
entry = sCorePriorityHeap->PeekRoot();
} else if (sPackageUsageHeap->PeekMinimum() != NULL) {
// wake new core
PackageEntry* package = sPackageUsageHeap->PeekMinimum();
@ -716,9 +728,9 @@ affine_choose_core_power_saving(int32 priority)
static inline int32
affine_choose_core(int32 priority)
affine_choose_core(Thread* thread)
{
return sChooseCore(priority);
return sChooseCore(thread);
}
@ -746,9 +758,7 @@ affine_should_rebalance(Thread* thread)
// than the average get rid of this one.
if (schedulerThreadData->additional_penalty != 0) {
int32 averageCPUBound = sCPUBoundThreads / sRunQueueCount;
if (coreEntry->fCPUBoundThreads - averageCPUBound > 1)
return true;
return false;
return coreEntry->fCPUBoundThreads - averageCPUBound > 1;
}
// If this thread is not cpu bound but we have at least one consider giving
@ -762,6 +772,11 @@ affine_should_rebalance(Thread* thread)
}
}
// Try our luck at small task packing.
int32 penalty = schedulerThreadData->priority_penalty;
if (!sDisableSmallTaskPacking && penalty == 0)
return sSmallTaskCore != coreEntry->fCoreID;
// No cpu bound threads - the situation is quite good. Make sure it
// won't get much worse...
const int32 kBalanceThreshold = 3;
@ -861,7 +876,7 @@ affine_enqueue(Thread* thread, bool newOne)
if (!newOne)
affine_thread_goes_away(thread);
targetCore = affine_choose_core(threadPriority);
targetCore = affine_choose_core(thread);
targetCPU = affine_choose_cpu(targetCore);
}
@ -1325,10 +1340,12 @@ affine_set_operation_mode(scheduler_mode mode)
sSchedulerMode = mode;
switch (mode) {
case SCHEDULER_MODE_PERFORMANCE:
sDisableSmallTaskPacking = true;
sChooseCore = affine_choose_core_performance;
break;
case SCHEDULER_MODE_POWER_SAVING:
sDisableSmallTaskPacking = false;
sChooseCore = affine_choose_core_power_saving;
break;