src/ck-ldb/DistributedLB.h

   1 /**
   2  * Author: gplkrsh2@illinois.edu (Harshitha Menon)
   3  *
   4  * A distributed load balancer which consists of two phases.
   5  * 1. Information propagation
   6  * 2. Probabilistic transfer of load
   7  *
   8  * Information propagation is done using Gossip protocol where the information
   9  * about the underloaded processors in the system is spread to the overloaded
  10  * processors.
  11  * Once the overloaded processors receive the partial information about the
  12  * underloaded processors in the system, it does probabilistic load transfer.
  13  * The probability of a PE receiving load is inversely proportional to its
  14  * current load.
  15 */
  16
  17 #ifndef _DISTLB_H_
  18 #define _DISTLB_H_
  19
  20 #include "DistBaseLB.h"
  21 #include "DistributedLB.decl.h"
  22
  23 #include "ckheap.h"
  24
  25 #include <vector>
  26
  27 void CreateDistributedLB();
  28
  29 class DistributedLB : public CBase_DistributedLB {
  30 public:
  31   DistributedLB(const CkLBOptions &);
  32   DistributedLB(CkMigrateMessage *m);
  33   void GossipLoadInfo(int, int, int, int[], double[]);
  34   void AvgLoadReduction(double x);
  35   void DoneGossip();
  36   void InformMigration(int obj_id, int from_pe, double obj_load, bool force);
  37   void RecvAck(int obj_id, int assigned_pe, bool can_accept);
  38   void SendAfterBarrier(CkReductionMsg *msg);
  39
  40 private:
  41   CProxy_DistributedLB thisProxy;
  42
  43   int underloaded_pe_count;
  44   std::vector<int> pe_no;
  45   std::vector<double> loads;
  46   std::vector<double> distribution;
  47
  48   int total_migrates_ack;
  49   int total_migrates;
  50   std::vector<MigrateInfo*> migrateInfo;
  51   LBMigrateMsg* msg;
  52
  53   bool kUseAck;
  54   double kTransferThreshold;
  55   int kPartialInfoCount;
  56   int kMaxTrials;
  57   int kMaxGossipMsgCount;
  58
  59   int gossip_msg_count;
  60   bool lb_started;
  61   int objs_count;
  62         double my_load;
  63         double avg_load;
  64   double b_load;
  65   double b_load_per_obj;
  66   double thr_avg;
  67         int req_hop;
  68   int negack_count;
  69
  70   const DistBaseLB::LDStats* my_stats;
  71
  72   void InitLB(const CkLBOptions &);
  73   void SendLoadInfo();
  74   void LoadBalance();
  75   void LoadBalance(CkVec<int> &obj_no, CkVec<int> &obj_pe_no);
  76   void MapObjsToPe(minHeap &objs, CkVec<int> &obj_no, CkVec<int> &obj_pe_no);
  77         int PickRandReceiverPeIdx() const;
  78         void CalculateCumulateDistribution();
  79   void Strategy(const DistBaseLB::LDStats* const stats);
  80
  81   bool QueryBalanceNow(int step) { return true; };
  82 };
  83
  84 #endif /* _DistributedLB_H_ */