diff options
| -rw-r--r-- | src/include/kernel/timemgr.H | 85 | ||||
| -rw-r--r-- | src/include/util/locked/pqueue.H | 283 | ||||
| -rw-r--r-- | src/kernel/scheduler.C | 56 | ||||
| -rw-r--r-- | src/kernel/timemgr.C | 95 | ||||
| -rw-r--r-- | src/lib/syscall_time.C | 51 |
5 files changed, 344 insertions, 226 deletions
diff --git a/src/include/kernel/timemgr.H b/src/include/kernel/timemgr.H index 96950b928..3f6d658d7 100644 --- a/src/include/kernel/timemgr.H +++ b/src/include/kernel/timemgr.H @@ -1,25 +1,26 @@ -// IBM_PROLOG_BEGIN_TAG -// This is an automatically generated prolog. -// -// $Source: src/include/kernel/timemgr.H $ -// -// IBM CONFIDENTIAL -// -// COPYRIGHT International Business Machines Corp. 2010 - 2011 -// -// p1 -// -// Object Code Only (OCO) source materials -// Licensed Internal Code Source Materials -// IBM HostBoot Licensed Internal Code -// -// The source code for this program is not published or other- -// wise divested of its trade secrets, irrespective of what has -// been deposited with the U.S. Copyright Office. -// -// Origin: 30 -// -// IBM_PROLOG_END +/* IBM_PROLOG_BEGIN_TAG + * This is an automatically generated prolog. + * + * $Source: src/include/kernel/timemgr.H $ + * + * IBM CONFIDENTIAL + * + * COPYRIGHT International Business Machines Corp. 2010-2012 + * + * p1 + * + * Object Code Only (OCO) source materials + * Licensed Internal Code Source Materials + * IBM HostBoot Licensed Internal Code + * + * The source code for this program is not published or other- + * wise divested of its trade secrets, irrespective of what has + * been deposited with the U.S. Copyright Office. + * + * Origin: 30 + * + * IBM_PROLOG_END_TAG + */ #ifndef __KERNEL_TIMEMGR_H #define __KERNEL_TIMEMGR_H @@ -48,13 +49,22 @@ class TimeManager { public: enum - { - /** Number of time-slices to allow per second. - * - * Context length becomes (1/TIMESLICE_PER_SECOND) sec. - */ - TIMESLICE_PER_SEC = 1000, - }; + { + /** Number of time-slices to allow per second. + * + * Context length becomes (1/TIMESLICE_PER_SECOND) sec. + */ + TIMESLICE_PER_SEC = 1000, + + /** Yield Threshold per timeslice + * + * @note At 512MHZ clock and TIMESLICE_PER_SEC = 1000, + * Timeslice = 512000 ticks. + * If threshold/slice = 100 then threhold = 5120 ticks + * FYI, a Context switch ~ 476 ticks + */ + YIELD_THRESHOLD_PER_SLICE = 100, // 1% + }; /** Initialize the time subsystem. */ static void init(); @@ -68,6 +78,21 @@ class TimeManager return iv_timebaseFreq / TIMESLICE_PER_SEC; }; + /** + * Return the number of ticks for an idle time-slice + */ + static uint64_t getIdleTimeSliceCount(); + + /** + * Perform a simple delay if the time is below the yield threshold. + * + * @param[in] sec, Delay time in seconds + * @param[in] nsec, Delay time in nano seconds + * @return false if the delay requires a task yield | true - The + * requested delay was performed by this routine. + */ + static bool simpleDelay(uint64_t sec, uint64_t nsec); + /** Returns the value of the processor timebase register. */ static uint64_t getCurrentTimeBase() { @@ -117,7 +142,7 @@ class TimeManager void _init_cpu(cpu_t* cpu); void _delayTask(task_t* t, uint64_t i_sec, uint64_t i_nsec); void _checkReleaseTasks(Scheduler* s); - inline delaylist_t* _get_delaylist(); + static delaylist_t* _get_delaylist(); /** Frequency of the timebase register in Hz. (ticks per second) */ static uint64_t iv_timebaseFreq; diff --git a/src/include/util/locked/pqueue.H b/src/include/util/locked/pqueue.H index 8e21a01d8..2a6324fe6 100644 --- a/src/include/util/locked/pqueue.H +++ b/src/include/util/locked/pqueue.H @@ -1,25 +1,26 @@ -// IBM_PROLOG_BEGIN_TAG -// This is an automatically generated prolog. -// -// $Source: src/include/util/locked/pqueue.H $ -// -// IBM CONFIDENTIAL -// -// COPYRIGHT International Business Machines Corp. 2010 - 2011 -// -// p1 -// -// Object Code Only (OCO) source materials -// Licensed Internal Code Source Materials -// IBM HostBoot Licensed Internal Code -// -// The source code for this program is not published or other- -// wise divested of its trade secrets, irrespective of what has -// been deposited with the U.S. Copyright Office. -// -// Origin: 30 -// -// IBM_PROLOG_END +/* IBM_PROLOG_BEGIN_TAG + * This is an automatically generated prolog. + * + * $Source: src/include/util/locked/pqueue.H $ + * + * IBM CONFIDENTIAL + * + * COPYRIGHT International Business Machines Corp. 2010-2012 + * + * p1 + * + * Object Code Only (OCO) source materials + * Licensed Internal Code Source Materials + * IBM HostBoot Licensed Internal Code + * + * The source code for this program is not published or other- + * wise divested of its trade secrets, irrespective of what has + * been deposited with the U.S. Copyright Office. + * + * Origin: 30 + * + * IBM_PROLOG_END_TAG + */ #ifndef __UTIL_LOCKED_PQUEUE_H #define __UTIL_LOCKED_PQUEUE_H @@ -29,108 +30,146 @@ namespace Util { namespace Locked { - template <typename _T, typename _K, - bool locked = false, typename _S = int> - class PQueue : public Queue<_T, locked, _S> - { - public: - void insert(_T*); - _T* remove_if(_K&); - - private: - void bubbleUp(_T*); - }; - - template <typename _T, typename _K, bool locked, typename _S> - void PQueue<_T,_K,locked,_S>::insert(_T* item) - { - this->__lock(); - - if (this->head == NULL) - { - item->next = item->prev = NULL; - this->head = this->tail = item; - } - else - { - item->prev = NULL; - item->next = this->head; - this->head = this->head->prev = item; - - bubbleUp(item); - } - - this->__unlock(); - } - - template <typename _T, typename _K, bool locked, typename _S> - _T* PQueue<_T,_K,locked,_S>::remove_if(_K& key) - { - _T* item = NULL; - - this->__lock(); - - if ((this->tail != NULL) && (this->tail->key <= key)) - { - item = this->tail; - if (this->head == this->tail) - this->head = this->tail = NULL; - else - this->tail = item->prev; + template <typename _T, typename _K, + bool locked = false, typename _S = int> + class PQueue : public Queue<_T, locked, _S> + { + public: + void insert(_T*); + _T* remove_if(_K&); + _T* front(); + + private: + void bubbleUp(_T*); + }; + + // SFINAE template to ensure compile fails if functions which are not + // SMP-safe are used on a 'locked' instance. + template<bool locked> + class __verify_pqueue_is_smp_safe + { + public: + __verify_pqueue_is_smp_safe() + { + class __util_locked_pqueue_is_not_smp_safe; + __util_locked_pqueue_is_not_smp_safe(); + } + }; + + // SFINAE template implementation to allow certain functions when the + // instance is not 'locked', assuming that caller is ensuring safety + // in some other way. + template<> + class __verify_pqueue_is_smp_safe<false> + { + public: + __verify_pqueue_is_smp_safe() + { + } + }; + + + template <typename _T, typename _K, bool locked, typename _S> + void PQueue<_T,_K,locked,_S>::insert(_T* item) + { + this->__lock(); + + if (this->head == NULL) + { + item->next = item->prev = NULL; + this->head = this->tail = item; + } + else + { + item->prev = NULL; + item->next = this->head; + this->head = this->head->prev = item; + + bubbleUp(item); + } + + this->__unlock(); + } + + template <typename _T, typename _K, bool locked, typename _S> + _T* PQueue<_T,_K,locked,_S>::remove_if(_K& key) + { + _T* item = NULL; + + this->__lock(); + + if ((this->tail != NULL) && (this->tail->key <= key)) + { + item = this->tail; + if (this->head == this->tail) + this->head = this->tail = NULL; + else + this->tail = item->prev; + + if (item->prev) + item->prev->next = NULL; + } + + this->__unlock(); + + return item; + } + + + template <typename _T, typename _K, bool locked, typename _S> + void PQueue<_T,_K,locked,_S>::bubbleUp(_T* item) + { + if (!item->next) + return; + + if (item->next->key <= item->key) + return; + + if (this->head == item) + this->head = item->next; + if (this->tail == item->next) + this->tail = item; + + _T* temp = item->next; + + if (temp->next) + { + temp->next->prev = item; + item->next = item->next->next; + } + else + { + item->next = NULL; + } if (item->prev) - item->prev->next = NULL; - } - - this->__unlock(); - - return item; - } - - - template <typename _T, typename _K, bool locked, typename _S> - void PQueue<_T,_K,locked,_S>::bubbleUp(_T* item) - { - if (!item->next) - return; - - if (item->next->key <= item->key) - return; - - if (this->head == item) - this->head = item->next; - if (this->tail == item->next) - this->tail = item; - - _T* temp = item->next; - - if (temp->next) - { - temp->next->prev = item; - item->next = item->next->next; - } - else - { - item->next = NULL; - } - - if (item->prev) - { - item->prev->next = temp; - temp->prev = item->prev; - } - else - { - temp->prev = NULL; - } - - temp->next = item; - item->prev = temp; - - bubbleUp(item); - } - - + { + item->prev->next = temp; + temp->prev = item->prev; + } + else + { + temp->prev = NULL; + } + + temp->next = item; + item->prev = temp; + + bubbleUp(item); + } + + + template <typename _T, typename _K, bool locked, typename _S> + _T* PQueue<_T, _K,locked,_S>::front() + { + // Entirely not SMP-safe to return a pointer to a node if + // we are a locking instance. If we aren't locking we + // have to assume that the caller is ensuring SMP-safety + // globally in some other way. Use SFINAE technique to + // ensure front() fails on locked lists. + __verify_pqueue_is_smp_safe<locked>(); + return this->tail; + } }; }; diff --git a/src/kernel/scheduler.C b/src/kernel/scheduler.C index 10dda6708..c545eb45a 100644 --- a/src/kernel/scheduler.C +++ b/src/kernel/scheduler.C @@ -1,25 +1,26 @@ -// IBM_PROLOG_BEGIN_TAG -// This is an automatically generated prolog. -// -// $Source: src/kernel/scheduler.C $ -// -// IBM CONFIDENTIAL -// -// COPYRIGHT International Business Machines Corp. 2010 - 2011 -// -// p1 -// -// Object Code Only (OCO) source materials -// Licensed Internal Code Source Materials -// IBM HostBoot Licensed Internal Code -// -// The source code for this program is not published or other- -// wise divested of its trade secrets, irrespective of what has -// been deposited with the U.S. Copyright Office. -// -// Origin: 30 -// -// IBM_PROLOG_END +/* IBM_PROLOG_BEGIN_TAG + * This is an automatically generated prolog. + * + * $Source: src/kernel/scheduler.C $ + * + * IBM CONFIDENTIAL + * + * COPYRIGHT International Business Machines Corp. 2010-2012 + * + * p1 + * + * Object Code Only (OCO) source materials + * Licensed Internal Code Source Materials + * IBM HostBoot Licensed Internal Code + * + * The source code for this program is not published or other- + * wise divested of its trade secrets, irrespective of what has + * been deposited with the U.S. Copyright Office. + * + * Origin: 30 + * + * IBM_PROLOG_END_TAG + */ #include <kernel/task.H> #include <kernel/scheduler.H> #include <kernel/taskmgr.H> @@ -39,8 +40,8 @@ void Scheduler::addTask(task_t* t) if (0 != t->affinity_pinned) { // Allocate a per-CPU queue if this is the first pinning to CPU. - Util::Lockfree::atomic_construct( - reinterpret_cast<Runqueue_t**>(&t->cpu->scheduler_extra)); + Util::Lockfree::atomic_construct + (reinterpret_cast<Runqueue_t**>(&t->cpu->scheduler_extra)); // Insert into queue. static_cast<Runqueue_t*>(t->cpu->scheduler_extra)->insert(t); @@ -48,7 +49,7 @@ void Scheduler::addTask(task_t* t) // Not pinned, add to global run-queue. else { - iv_taskList.insert(t); + iv_taskList.insert(t); } } } @@ -96,9 +97,8 @@ void Scheduler::setNextRunnable() // Choose idle task if no other ready task is available. if (NULL == t) { - t = cpu->idle_task; - // TODO: Set short decrementer. - setDEC(TimeManager::getTimeSliceCount()); + t = cpu->idle_task; + setDEC(TimeManager::getIdleTimeSliceCount()); } else // Set normal timeslice to decrementer. { diff --git a/src/kernel/timemgr.C b/src/kernel/timemgr.C index 36d89ee30..32ffa4a68 100644 --- a/src/kernel/timemgr.C +++ b/src/kernel/timemgr.C @@ -1,25 +1,26 @@ -// IBM_PROLOG_BEGIN_TAG -// This is an automatically generated prolog. -// -// $Source: src/kernel/timemgr.C $ -// -// IBM CONFIDENTIAL -// -// COPYRIGHT International Business Machines Corp. 2010 - 2011 -// -// p1 -// -// Object Code Only (OCO) source materials -// Licensed Internal Code Source Materials -// IBM HostBoot Licensed Internal Code -// -// The source code for this program is not published or other- -// wise divested of its trade secrets, irrespective of what has -// been deposited with the U.S. Copyright Office. -// -// Origin: 30 -// -// IBM_PROLOG_END +/* IBM_PROLOG_BEGIN_TAG + * This is an automatically generated prolog. + * + * $Source: src/kernel/timemgr.C $ + * + * IBM CONFIDENTIAL + * + * COPYRIGHT International Business Machines Corp. 2010-2012 + * + * p1 + * + * Object Code Only (OCO) source materials + * Licensed Internal Code Source Materials + * IBM HostBoot Licensed Internal Code + * + * The source code for this program is not published or other- + * wise divested of its trade secrets, irrespective of what has + * been deposited with the U.S. Copyright Office. + * + * Origin: 30 + * + * IBM_PROLOG_END_TAG + */ #include <kernel/timemgr.H> #include <kernel/scheduler.H> #include <util/singleton.H> @@ -105,7 +106,55 @@ void TimeManager::_checkReleaseTasks(Scheduler* s) } } -inline TimeManager::delaylist_t* TimeManager::_get_delaylist() +TimeManager::delaylist_t* TimeManager::_get_delaylist() { return static_cast<delaylist_t*>(CpuManager::getCurrentCPU()->delay_list); } + +uint64_t TimeManager::getIdleTimeSliceCount() +{ + uint64_t sliceCount = getTimeSliceCount(); + + // Get a delayed task, if there is one + _TimeManager_Delay_t* node = _get_delaylist()->front(); + + if(node) + { + uint64_t currentTime = getCurrentTimeBase(); + if(currentTime < node->key) + { + uint64_t diffTime = node->key - currentTime; + if(diffTime < sliceCount) + { + sliceCount = diffTime; + } + } + else // ready to run now! Minimum delay + { + sliceCount = 1; + } + } + return sliceCount; +} + +bool TimeManager::simpleDelay(uint64_t i_sec, uint64_t i_nsec) +{ + bool result = false; + + uint64_t threshold = getTimeSliceCount()/YIELD_THRESHOLD_PER_SLICE; + uint64_t delay = convertSecToTicks(i_sec, i_nsec); + + if(delay < threshold) + { + uint64_t expire = getCurrentTimeBase() + delay; + while(getCurrentTimeBase() < expire) + { + setThreadPriorityLow(); + } + setThreadPriorityHigh(); + result = true; + } + + return result; +} + diff --git a/src/lib/syscall_time.C b/src/lib/syscall_time.C index 819b605b0..2fb56cb68 100644 --- a/src/lib/syscall_time.C +++ b/src/lib/syscall_time.C @@ -1,25 +1,26 @@ -// IBM_PROLOG_BEGIN_TAG -// This is an automatically generated prolog. -// -// $Source: src/lib/syscall_time.C $ -// -// IBM CONFIDENTIAL -// -// COPYRIGHT International Business Machines Corp. 2010 - 2011 -// -// p1 -// -// Object Code Only (OCO) source materials -// Licensed Internal Code Source Materials -// IBM HostBoot Licensed Internal Code -// -// The source code for this program is not published or other- -// wise divested of its trade secrets, irrespective of what has -// been deposited with the U.S. Copyright Office. -// -// Origin: 30 -// -// IBM_PROLOG_END +/* IBM_PROLOG_BEGIN_TAG + * This is an automatically generated prolog. + * + * $Source: src/lib/syscall_time.C $ + * + * IBM CONFIDENTIAL + * + * COPYRIGHT International Business Machines Corp. 2010-2012 + * + * p1 + * + * Object Code Only (OCO) source materials + * Licensed Internal Code Source Materials + * IBM HostBoot Licensed Internal Code + * + * The source code for this program is not published or other- + * wise divested of its trade secrets, irrespective of what has + * been deposited with the U.S. Copyright Office. + * + * Origin: 30 + * + * IBM_PROLOG_END_TAG + */ #include <time.h> #include <sys/time.h> #include <sys/syscall.h> @@ -30,7 +31,11 @@ using namespace Systemcalls; void nanosleep(uint64_t sec, uint64_t nsec) { - _syscall2(TIME_NANOSLEEP, (void*)sec, (void*)nsec); + // If the delay is short then simpleDelay() will perform the delay + if(unlikely(!TimeManager::simpleDelay(sec, nsec))) + { + _syscall2(TIME_NANOSLEEP, (void*)sec, (void*)nsec); + } } int clock_gettime(clockid_t clk_id, timespec_t* tp) |
