Changeset 772411a

Timestamp:

Aug 25, 2020, 11:33:44 AM (3 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

d168fefe

Parents:

97cba9f

Message:

Moved bias to it's own function.
Fixed minor assertions triggering.

Location:

libcfa/src/concurrency

Files:

• kernel/startup.cfa (modified) (4 diffs)
• ready_queue.cfa (modified) (7 diffs)

libcfa/src/concurrency/kernel/startup.cfa

@@ -579 +579 @@
 
         // Lock the RWlock so no-one pushes/pops while we are changing the queue
+        disable_interrupts();
         uint_fast32_t last_size = ready_mutate_lock();
 
@@ -586 +587 @@
         // Unlock the RWlock
         ready_mutate_unlock( last_size );
+        enable_interrupts_noPoll(); // Don't poll, could be in main cluster
+
 
         this.io.cnt  = num_io;
@@ -601 +604 @@
 
         // Lock the RWlock so no-one pushes/pops while we are changing the queue
+        disable_interrupts();
         uint_fast32_t last_size = ready_mutate_lock();
 
@@ -608 +612 @@
         // Unlock the RWlock
         ready_mutate_unlock( last_size );
+        enable_interrupts_noPoll(); // Don't poll, could be in main cluster
 
         #if !defined(__CFA_NO_STATISTICS__)

libcfa/src/concurrency/ready_queue.cfa

@@ -215 +215 @@
 }
 
+static inline [unsigned, bool] idx_from_r(unsigned r, unsigned preferred) {
+        unsigned i;
+        bool local;
+        #if defined(BIAS)
+                unsigned rlow  = r % BIAS;
+                unsigned rhigh = r / BIAS;
+                if((0 != rlow) && preferred >= 0) {
+                        // (BIAS - 1) out of BIAS chances
+                        // Use perferred queues
+                        i = preferred + (rhigh % 4);
+                        local = true;
+                }
+                else {
+                        // 1 out of BIAS chances
+                        // Use all queues
+                        i = rhigh;
+                        local = false;
+                }
+        #else
+                i = r;
+                local = false;
+        #endif
+        return [i, local];
+}
+
 //-----------------------------------------------------------------------
 __attribute__((hot)) bool push(struct cluster * cltr, struct $thread * thrd) with (cltr->ready_queue) {
@@ -222 +247 @@
         thrd->link.ts = rdtscl();
 
-        #if defined(BIAS) && !defined(__CFA_NO_STATISTICS__)
-                bool local = false;
-                int preferred =
+        __attribute__((unused)) bool local;
+        __attribute__((unused)) int preferred;
+        #if defined(BIAS)
+                preferred =
                         //*
                         kernelTLS.this_processor ? kernelTLS.this_processor->id * 4 : -1;
@@ -230 +256 @@
                         thrd->link.preferred * 4;
                         //*/
-
-
         #endif
 
@@ -238 +262 @@
         do {
                 // Pick the index of a lane
-                #if defined(BIAS)
-                        unsigned r = __tls_rand();
-                        unsigned rlow  = r % BIAS;
-                        unsigned rhigh = r / BIAS;
-                        if((0 != rlow) && preferred >= 0) {
-                                // (BIAS - 1) out of BIAS chances
-                                // Use perferred queues
-                                i = preferred + (rhigh % 4);
-
-                                #if !defined(__CFA_NO_STATISTICS__)
-                                        local = true;
-                                        __tls_stats()->ready.pick.push.local++;
-                                #endif
-                        }
-                        else {
-                                // 1 out of BIAS chances
-                                // Use all queues
-                                i = rhigh;
-                                local = false;
-                        }
-                #else
-                        i = __tls_rand();
+                unsigned r = __tls_rand();
+                [i, local] = idx_from_r(r, preferred);
+
+                #if !defined(__CFA_NO_STATISTICS__)
+                        if(local) {
+                                __tls_stats()->ready.pick.push.local++;
+                        }
                 #endif
 
@@ -311 +320 @@
         /* paranoid */ verify( lanes.count > 0 );
         unsigned count = __atomic_load_n( &lanes.count, __ATOMIC_RELAXED );
+        int preferred;
         #if defined(BIAS)
                 // Don't bother trying locally too much
                 int local_tries = 8;
-        #endif
+                preferred = kernelTLS.this_processor->id * 4;
+        #endif
+
 
         // As long as the list is not empty, try finding a lane that isn't empty and pop from it
@@ -323 +335 @@
         #endif
                 // Pick two lists at random
-                unsigned i,j;
-                #if defined(BIAS)
-                        #if !defined(__CFA_NO_STATISTICS__)
-                                bool local = false;
-                        #endif
-                        uint64_t r = __tls_rand();
-                        unsigned rlow  = r % BIAS;
-                        uint64_t rhigh = r / BIAS;
-                        if(local_tries && 0 != rlow) {
-                                // (BIAS - 1) out of BIAS chances
-                                // Use perferred queues
-                                unsigned pid = kernelTLS.this_processor->id * 4;
-                                i = pid + (rhigh % 4);
-                                j = pid + ((rhigh >> 32ull) % 4);
-
-                                // count the tries
-                                local_tries--;
-
-                                #if !defined(__CFA_NO_STATISTICS__)
-                                        local = true;
-                                        __tls_stats()->ready.pick.pop.local++;
-                                #endif
-                        }
-                        else {
-                                // 1 out of BIAS chances
-                                // Use all queues
-                                i = rhigh;
-                                j = rhigh >> 32ull;
-                        }
-                #else
-                        i = __tls_rand();
-                        j = __tls_rand();
+                unsigned ri = __tls_rand();
+                unsigned rj = __tls_rand();
+
+                unsigned i, j;
+                __attribute__((unused)) bool locali, localj;
+                [i, locali] = idx_from_r(ri, preferred);
+                [j, localj] = idx_from_r(rj, preferred);
+
+                #if !defined(__CFA_NO_STATISTICS__)
+                        if(locali) {
+                                __tls_stats()->ready.pick.pop.local++;
+                        }
+                        if(localj) {
+                                __tls_stats()->ready.pick.pop.local++;
+                        }
                 #endif
 
@@ -364 +359 @@
                 if(thrd) {
                         #if defined(BIAS) && !defined(__CFA_NO_STATISTICS__)
-                                if( local ) __tls_stats()->ready.pick.pop.lsuccess++;
+                                if( locali || localj ) __tls_stats()->ready.pick.pop.lsuccess++;
                         #endif
                         return thrd;