litmus-rt.git - The LITMUS^RT kernel.

The LITMUS^RT kernel.

Bjoern Brandenburg

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author	Rusty Russell <rusty@rustcorp.com.au>	2009-03-15 23:42:40 -0400
committer	Rusty Russell <rusty@rustcorp.com.au>	2009-03-15 23:42:40 -0400
commit	d4e3676dba299e24acb66de6da2a0bb44d0d2414 (patch)
tree	e7df56f7b2b8eea4391f6587a304db89e5f72625 /lib/dump_stack.c
parent	5bee17f18b595937e6beafeee5197868a3f74a06 (diff)

cpumask: remove the now-obsoleted pcibus_to_cpumask(): ia64

Impact: reduce stack usage for large NR_CPUS cpumask_of_pcibus() is the new version. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Diffstat (limited to 'lib/dump_stack.c')

0 files changed, 0 insertions, 0 deletions

class="hl kwb">unsigned long wcet, unsigned long period, unsigned long deadline, unsigned long prio_pt, unsigned long request_span) { this->wcet = wcet; this->period = period; if (!deadline) this->deadline = period; // implicit else this->deadline = deadline; if (!prio_pt) this->prio_pt = deadline; else this->prio_pt = prio_pt; this->request_span = request_span; } bool Task::has_implicit_deadline() const { return deadline == period; } bool Task::has_constrained_deadline() const { return deadline <= period; } bool Task::is_feasible() const { return get_deadline() >= get_wcet() && get_period() >= get_wcet() && get_wcet() > 0; } void Task::get_utilization(fractional_t &util) const { // assumes period != 0 util = get_wcet(); util /= get_period(); } void Task::get_density(fractional_t &density) const { // assumes deadline != 0 density = get_wcet(); density /= get_deadline(); } std::ostream& operator<<(std::ostream &os, const Task &t) { os << "Task(" << t.get_wcet() << ", " << t.get_period(); if (!t.has_implicit_deadline()) os << ", " << t.get_deadline(); os << ")"; return os; } TaskSet::TaskSet() { } TaskSet::TaskSet(const TaskSet &original) : tasks(original.tasks) { } TaskSet::~TaskSet() { } #define FORALL(i, pred) \ for (unsigned int i = 0; i < tasks.size(); i++) \ { \ if (!pred) \ return false; \ } \ return true; \ bool TaskSet::has_only_implicit_deadlines() const { FORALL(i, tasks[i].has_implicit_deadline()); } bool TaskSet::has_only_constrained_deadlines() const { FORALL(i, tasks[i].has_constrained_deadline()); } bool TaskSet::has_only_feasible_tasks() const { FORALL(i, tasks[i].is_feasible()); } void TaskSet::get_utilization(fractional_t &util) const { fractional_t tmp; util = 0; for (unsigned int i = 0; i < tasks.size(); i++) { tasks[i].get_utilization(tmp); util += tmp; } } void TaskSet::get_density(fractional_t &density) const { fractional_t tmp; density = 0; for (unsigned int i = 0; i < tasks.size(); i++) { tasks[i].get_density(tmp); density += tmp; } } void TaskSet::get_max_density(fractional_t &max_density) const { fractional_t tmp; max_density = 0; for (unsigned int i = 0; i < tasks.size(); i++) { tasks[i].get_density(tmp); max_density = std::max(max_density, tmp); } } bool TaskSet::is_not_overutilized(unsigned int num_processors) const { fractional_t util; get_utilization(util); return util <= num_processors; } // Lemma 7 in FBB:06. unsigned long TaskSet::k_for_epsilon(unsigned int idx, const fractional_t &epsilon) const { fractional_t bound; fractional_t dp_ratio(tasks[idx].get_deadline(), tasks[idx].get_period()); tasks[idx].get_utilization(bound); bound *= tasks.size(); bound /= epsilon; bound -= dp_ratio; return (unsigned long) ceil(std::max(0.0, bound.get_d())); } void TaskSet::bound_demand(const integral_t &time, integral_t &demand) const { integral_t task_demand; demand = 0; for (unsigned int i = 0; i < tasks.size(); i++) { tasks[i].bound_demand(time, task_demand); demand += task_demand; } } void TaskSet::approx_load(fractional_t &load, const fractional_t &epsilon) const { fractional_t density; get_density(density); get_utilization(load); if (density > load) { // ok, actually have to do the work; load += epsilon; std::vector<unsigned long> k; k.reserve(tasks.size()); unsigned long total_times = tasks.size(); for (unsigned int i = 0; i < tasks.size(); i++) { k[i] = k_for_epsilon(i, epsilon); total_times += k[i]; } std::cout << "total_times = " << total_times << std::endl; std::vector<integral_t> times; times.reserve(total_times); // determine all test points for (unsigned int i = 0; i < tasks.size(); i++) { integral_t time = tasks[i].get_deadline(); for (unsigned long j = 0; j <= k[i]; j++) { times.push_back(time); time += tasks[i].get_period(); } } // sort times std::sort(times.begin(), times.end()); // iterate through test points integral_t last = 0; for (unsigned int t = 0; t < total_times; t++) { // avoid redundant check if (times[t] > last) { fractional_t load_at_point = 0; fractional_t tmp; // compute approximate load at point for (unsigned int i = 0; i < tasks.size(); i++) { tasks[i].approx_load(times[t], tmp, k[i]); load_at_point += tmp; } // check if we have a new maximum if (load_at_point > density) { // reached threshold, can stop iteration load = density; return; } else if (load_at_point > load) load = load_at_point; last = times[t]; } } } }


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