# HG changeset patch
# User Merten Sach <msach@mailbox.tu-berlin.de>
# Date 1328292004 -3600
# Node ID f89bf9e368f546df5deeef8698e21fd394917f9f
# Parent  c66137e4dc2f65ebdfbee157987e95cf86544511
tuning of backoff on xoanon

diff -r c66137e4dc2f -r f89bf9e368f5 CoreLoop.c
--- a/CoreLoop.c	Fri Jan 13 11:49:05 2012 +0100
+++ b/CoreLoop.c	Fri Feb 03 19:00:04 2012 +0100
@@ -47,6 +47,8 @@
    int32           numMasterInARow = 0;
    volatile int32 *masterLock;
    VirtProcr      *masterVP;
+   
+   volatile double workspace1,workspace2; //variables for master lock busy waiting
 
    // init random number generator for retries
    uint32_t seed1 = rand()%1000;
@@ -141,11 +143,15 @@
       while( currVP == NULL ) //if queue was empty, enter get masterLock loop
        {    //queue was empty, so get master lock
 
-		 if(numMasterInARow > 2){
-		 	wait_iterations=(randomNumber(&seed1, &seed2) % (numMasterInARow*numMasterInARow))*100;
-	   		int i;
-	  	    for(i=0; i<wait_iterations; i++)/*busy wait*/;
-		 }
+	if(numMasterInARow > 2){
+                wait_iterations=(randomNumber(&seed1, &seed2) % (numMasterInARow*NUM_CORES));
+	   	int i;
+	  	for(i=0; i<wait_iterations; i++)
+                {/*busy wait*/
+                    workspace1 += (workspace1 + 32)/2;
+                }
+        }
+                 
          gotLock = __sync_bool_compare_and_swap(masterLock,
                                                 UNLOCKED, LOCKED );
          if( gotLock )
@@ -161,7 +167,10 @@
 	   wait_iterations=(randomNumber(&seed1, &seed2) % (tries+1))*100;
 	   //addToHist( wait_iterations, coreLoopThdParams->wait_iterations_hist );
 	   int i;
-	   for(i=0; i<wait_iterations; i++)/*busy wait*/;
+	   for(i=0; i<wait_iterations; i++)
+           {/*busy wait*/
+                workspace1 += (workspace1 + 32)/2;
+           }
 	}
 
          tries++;      //if too many, means master on other core taking too long
@@ -199,8 +208,10 @@
           _VMSMasterEnv->startMaster.longVal = endSusp.longVal;
           #endif
           //==================================================
-   }//CoreLoop      
- }
+   }//CoreLoop
+  
+   return (void*)&workspace1; //gcc fake out for -O3
+}
 
 inline uint32_t
 randomNumber(uint32_t* seed1, uint32_t* seed2){
diff -r c66137e4dc2f -r f89bf9e368f5 VMS_defs.h
--- a/VMS_defs.h	Fri Jan 13 11:49:05 2012 +0100
+++ b/VMS_defs.h	Fri Feb 03 19:00:04 2012 +0100
@@ -81,7 +81,7 @@
 
    // tradeoff amortizing master fixed overhead vs imbalance potential
    // when work-stealing, can make bigger, at risk of losing cache affinity
-#define NUM_SCHED_SLOTS  5
+#define NUM_SCHED_SLOTS  3
 
 #define MIN_WORK_UNIT_CYCLES 20000
 
@@ -91,7 +91,7 @@
 #define VIRT_PROCR_STACK_SIZE 0x8000 /* 32K */
 
    // memory for VMS__malloc
-#define MALLOC_ADDITIONAL_MEM_FROM_OS_SIZE 0x10000000 /* 256M */
+#define MALLOC_ADDITIONAL_MEM_FROM_OS_SIZE 0x40000000 /* 1G */
 
 #define CACHE_LINE 64
 #define PAGE_SIZE 4096