Remove code that lowers knowhere threads' priority (#54)

Signed-off-by: Buqian Zheng <[email protected]>

include/knowhere/comp/thread_pool.h

@@ -12,7 +12,6 @@
 #pragma once
 
 #include <omp.h>
-#include <pthread.h>
 
 #include <memory>
 #include <utility>
@@ -24,36 +23,13 @@
 namespace knowhere {
 
 class ThreadPool {
- private:
- class LowPriorityThreadFactory : public folly::NamedThreadFactory {
- public:
- using folly::NamedThreadFactory::NamedThreadFactory;
- std::thread
- newThread(folly::Func&& func) override {
- auto thread = folly::NamedThreadFactory::newThread(std::move(func));
- sched_param sch_params;
- int policy = SCHED_FIFO;
- sch_params.sched_priority = sched_get_priority_min(policy);
- int en = pthread_setschedparam(thread.native_handle(), policy, &sch_params);
- if (en) {
- LOG_KNOWHERE_ERROR_ << "Failed to set Thread scheduling : " << std::strerror(en) << std::endl;
- } else {
- LOG_KNOWHERE_DEBUG_ << "LowPriorityThreadFactory set thread priority to min: "
- << sch_params.sched_priority << ", max is " << sched_get_priority_max(policy)
- << " thread " << thread.get_id() << std::endl;
- }
- return thread;
- }
- };
-
  public:
  explicit ThreadPool(uint32_t num_threads)
  : pool_(folly::CPUThreadPoolExecutor(
  num_threads,
  std::make_unique<
  folly::LifoSemMPMCQueue<folly::CPUThreadPoolExecutor::CPUTask, folly::QueueBehaviorIfFull::BLOCK>>(
- num_threads * kTaskQueueFactor),
- std::make_shared<LowPriorityThreadFactory>("LowPrioKWPool"))) {
+ num_threads * kTaskQueueFactor))) {
  }
 
  ThreadPool(const ThreadPool&) = delete;