Merge branch 'dev' of https://github.com/accel-sim/gpgpu-sim_distribution into dev

1 files changed, 141 insertions, 52 deletions

diff --git a/src/gpgpu-sim/gpu-cache.cc b/src/gpgpu-sim/gpu-cache.cc
index c6a125d..297a94c 100644
--- a/src/gpgpu-sim/gpu-cache.cc
+++ b/src/gpgpu-sim/gpu-cache.cc
@@ -210,6 +210,7 @@ void tag_array::init(int core_id, int type_id) {
   m_core_id = core_id;
   m_type_id = type_id;
   is_used = false;
+  m_dirty = 0;
 }
 
 void tag_array::add_pending_line(mem_fetch *mf) {
@@ -231,15 +232,15 @@ void tag_array::remove_pending_line(mem_fetch *mf) {
 }
 
 enum cache_request_status tag_array::probe(new_addr_type addr, unsigned &idx,
-                                           mem_fetch *mf,
+                                           mem_fetch *mf, bool is_write,
                                            bool probe_mode) const {
   mem_access_sector_mask_t mask = mf->get_access_sector_mask();
-  return probe(addr, idx, mask, probe_mode, mf);
+  return probe(addr, idx, mask,is_write, probe_mode, mf);
 }
 
 enum cache_request_status tag_array::probe(new_addr_type addr, unsigned &idx,
                                            mem_access_sector_mask_t mask,
-                                           bool probe_mode,
+                                           bool is_write, bool probe_mode,
                                            mem_fetch *mf) const {
   // assert( m_config.m_write_policy == READ_ONLY );
   unsigned set_index = m_config.set_index(addr);
@@ -250,7 +251,6 @@ enum cache_request_status tag_array::probe(new_addr_type addr, unsigned &idx,
   unsigned long long valid_timestamp = (unsigned)-1;
 
   bool all_reserved = true;
-
   // check for hit or pending hit
   for (unsigned way = 0; way < m_config.m_assoc; way++) {
     unsigned index = set_index * m_config.m_assoc + way;
@@ -263,7 +263,7 @@ enum cache_request_status tag_array::probe(new_addr_type addr, unsigned &idx,
         idx = index;
         return HIT;
       } else if (line->get_status(mask) == MODIFIED) {
-        if (line->is_readable(mask)) {
+        if ((!is_write && line->is_readable(mask)) || is_write) {
           idx = index;
           return HIT;
         } else {
@@ -279,20 +279,29 @@ enum cache_request_status tag_array::probe(new_addr_type addr, unsigned &idx,
       }
     }
     if (!line->is_reserved_line()) {
-      all_reserved = false;
-      if (line->is_invalid_line()) {
-        invalid_line = index;
-      } else {
-        // valid line : keep track of most appropriate replacement candidate
-        if (m_config.m_replacement_policy == LRU) {
-          if (line->get_last_access_time() < valid_timestamp) {
-            valid_timestamp = line->get_last_access_time();
-            valid_line = index;
-          }
-        } else if (m_config.m_replacement_policy == FIFO) {
-          if (line->get_alloc_time() < valid_timestamp) {
-            valid_timestamp = line->get_alloc_time();
-            valid_line = index;
+      // percentage of dirty lines in the cache
+      // number of dirty lines / total lines in the cache
+      float dirty_line_percentage = 
+          (float) (m_dirty / (m_config.m_nset * m_config.m_assoc )) * 100;
+      if (!line->is_modified_line() ||
+          dirty_line_percentage >= m_config.m_wr_percent) {
+        // if number of dirty lines in the cache is greater than
+        // a specific value
+        all_reserved = false;
+        if (line->is_invalid_line()) {
+          invalid_line = index;
+        } else {
+          // valid line : keep track of most appropriate replacement candidate
+          if (m_config.m_replacement_policy == LRU) {
+            if (line->get_last_access_time() < valid_timestamp) {
+              valid_timestamp = line->get_last_access_time();
+              valid_line = index;
+            }
+          } else if (m_config.m_replacement_policy == FIFO) {
+            if (line->get_alloc_time() < valid_timestamp) {
+              valid_timestamp = line->get_alloc_time();
+              valid_line = index;
+            }
           }
         }
       }
@@ -331,7 +340,7 @@ enum cache_request_status tag_array::access(new_addr_type addr, unsigned time,
   m_access++;
   is_used = true;
   shader_cache_access_log(m_core_id, m_type_id, 0);  // log accesses to cache
-  enum cache_request_status status = probe(addr, idx, mf);
+  enum cache_request_status status = probe(addr, idx, mf, mf->is_write());
   switch (status) {
     case HIT_RESERVED:
       m_pending_hit++;
@@ -344,8 +353,12 @@ enum cache_request_status tag_array::access(new_addr_type addr, unsigned time,
       if (m_config.m_alloc_policy == ON_MISS) {
         if (m_lines[idx]->is_modified_line()) {
           wb = true;
+          m_lines[idx]->set_byte_mask(mf);
           evicted.set_info(m_lines[idx]->m_block_addr,
-                           m_lines[idx]->get_modified_size());
+                           m_lines[idx]->get_modified_size(),
+                           m_lines[idx]->get_dirty_byte_mask(),
+                            m_lines[idx]->get_dirty_sector_mask());
+          m_dirty--;
         }
         m_lines[idx]->allocate(m_config.tag(addr), m_config.block_addr(addr),
                                time, mf->get_access_sector_mask());
@@ -356,8 +369,12 @@ enum cache_request_status tag_array::access(new_addr_type addr, unsigned time,
       m_sector_miss++;
       shader_cache_access_log(m_core_id, m_type_id, 1);  // log cache misses
       if (m_config.m_alloc_policy == ON_MISS) {
+        bool before = m_lines[idx]->is_modified_line();
         ((sector_cache_block *)m_lines[idx])
             ->allocate_sector(time, mf->get_access_sector_mask());
+            if (before && !m_lines[idx]->is_modified_line()) {
+              m_dirty--;
+            }
       }
       break;
     case RESERVATION_FAIL:
@@ -374,31 +391,40 @@ enum cache_request_status tag_array::access(new_addr_type addr, unsigned time,
   return status;
 }
 
-void tag_array::fill(new_addr_type addr, unsigned time, mem_fetch *mf) {
-  fill(addr, time, mf->get_access_sector_mask());
+void tag_array::fill(new_addr_type addr, unsigned time, mem_fetch *mf, bool is_write) {
+  fill(addr, time, mf->get_access_sector_mask(), mf->get_access_byte_mask(), is_write);
 }
 
 void tag_array::fill(new_addr_type addr, unsigned time,
-                     mem_access_sector_mask_t mask) {
+                     mem_access_sector_mask_t mask, mem_access_byte_mask_t byte_mask,
+                     bool is_write) {
   // assert( m_config.m_alloc_policy == ON_FILL );
   unsigned idx;
-  enum cache_request_status status = probe(addr, idx, mask);
+  enum cache_request_status status = probe(addr, idx, mask,is_write);
+  bool before = m_lines[idx]->is_modified_line();
   // assert(status==MISS||status==SECTOR_MISS); // MSHR should have prevented
   // redundant memory request
-  if (status == MISS)
+  if (status == MISS) {
     m_lines[idx]->allocate(m_config.tag(addr), m_config.block_addr(addr), time,
                            mask);
-  else if (status == SECTOR_MISS) {
+  } else if (status == SECTOR_MISS) {
     assert(m_config.m_cache_type == SECTOR);
     ((sector_cache_block *)m_lines[idx])->allocate_sector(time, mask);
   }
-
-  m_lines[idx]->fill(time, mask);
+  if (before && !m_lines[idx]->is_modified_line()) {
+    m_dirty--;
+  }
+  before = m_lines[idx]->is_modified_line();
+  m_lines[idx]->fill(time, mask, byte_mask);
+  if (m_lines[idx]->is_modified_line() && !before) {
+    m_dirty++;
+  }
 }
 
 void tag_array::fill(unsigned index, unsigned time, mem_fetch *mf) {
   assert(m_config.m_alloc_policy == ON_MISS);
-  m_lines[index]->fill(time, mf->get_access_sector_mask());
+  m_lines[index]->fill(time, mf->get_access_sector_mask(), mf->get_access_byte_mask());
+  m_dirty++;
 }
 
 // TODO: we need write back the flushed data to the upper level
@@ -407,10 +433,12 @@ void tag_array::flush() {
 
   for (unsigned i = 0; i < m_config.get_num_lines(); i++)
     if (m_lines[i]->is_modified_line()) {
-      for (unsigned j = 0; j < SECTOR_CHUNCK_SIZE; j++)
+      for (unsigned j = 0; j < SECTOR_CHUNCK_SIZE; j++) {
         m_lines[i]->set_status(INVALID, mem_access_sector_mask_t().set(j));
+      }
     }
-
+  
+  m_dirty = 0;
   is_used = false;
 }
 
@@ -421,6 +449,7 @@ void tag_array::invalidate() {
     for (unsigned j = 0; j < SECTOR_CHUNCK_SIZE; j++)
       m_lines[i]->set_status(INVALID, mem_access_sector_mask_t().set(j));
 
+  m_dirty = 0;
   is_used = false;
 }
 
@@ -764,7 +793,9 @@ void cache_stats::print_stats(FILE *fout, const char *cache_name) const {
               cache_request_status_str((enum cache_request_status)status),
               m_stats[type][status]);
 
-      if (status != RESERVATION_FAIL)
+      if (status != RESERVATION_FAIL && status != MSHR_HIT)
+      // MSHR_HIT is a special type of SECTOR_MISS
+      // so its already included in the SECTOR_MISS
         total_access[type] += m_stats[type][status];
     }
   }
@@ -1050,7 +1081,7 @@ void baseline_cache::fill(mem_fetch *mf, unsigned time) {
   if (m_config.m_alloc_policy == ON_MISS)
     m_tag_array->fill(e->second.m_cache_index, time, mf);
   else if (m_config.m_alloc_policy == ON_FILL) {
-    m_tag_array->fill(e->second.m_block_addr, time, mf);
+    m_tag_array->fill(e->second.m_block_addr, time, mf, mf->is_write());
   } else
     abort();
   bool has_atomic = false;
@@ -1058,9 +1089,13 @@ void baseline_cache::fill(mem_fetch *mf, unsigned time) {
   if (has_atomic) {
     assert(m_config.m_alloc_policy == ON_MISS);
     cache_block_t *block = m_tag_array->get_block(e->second.m_cache_index);
+    if (!block->is_modified_line()) {
+      m_tag_array->inc_dirty();
+    }
     block->set_status(MODIFIED,
                       mf->get_access_sector_mask());  // mark line as dirty for
                                                       // atomic operation
+    block->set_byte_mask(mf);
   }
   m_extra_mf_fields.erase(mf);
   m_bandwidth_management.use_fill_port(mf);
@@ -1163,7 +1198,11 @@ cache_request_status data_cache::wr_hit_wb(new_addr_type addr,
   new_addr_type block_addr = m_config.block_addr(addr);
   m_tag_array->access(block_addr, time, cache_index, mf);  // update LRU state
   cache_block_t *block = m_tag_array->get_block(cache_index);
+  if (!block->is_modified_line()) {
+    m_tag_array->inc_dirty();
+  }
   block->set_status(MODIFIED, mf->get_access_sector_mask());
+  block->set_byte_mask(mf);
 
   return HIT;
 }
@@ -1182,7 +1221,11 @@ cache_request_status data_cache::wr_hit_wt(new_addr_type addr,
   new_addr_type block_addr = m_config.block_addr(addr);
   m_tag_array->access(block_addr, time, cache_index, mf);  // update LRU state
   cache_block_t *block = m_tag_array->get_block(cache_index);
+  if (!block->is_modified_line()) {
+    m_tag_array->inc_dirty();
+  }
   block->set_status(MODIFIED, mf->get_access_sector_mask());
+  block->set_byte_mask(mf);
 
   // generate a write-through
   send_write_request(mf, cache_event(WRITE_REQUEST_SENT), time, events);
@@ -1292,8 +1335,10 @@ enum cache_request_status data_cache::wr_miss_wa_naive(
       assert(status ==
              MISS);  // SECTOR_MISS and HIT_RESERVED should not send write back
       mem_fetch *wb = m_memfetch_creator->alloc(
-          evicted.m_block_addr, m_wrbk_type, evicted.m_modified_size, true,
-          m_gpu->gpu_tot_sim_cycle + m_gpu->gpu_sim_cycle);
+        evicted.m_block_addr,m_wrbk_type,
+        mf->get_access_warp_mask(), evicted.m_byte_mask,
+        evicted.m_sector_mask, evicted.m_modified_size,
+        true, m_gpu->gpu_tot_sim_cycle + m_gpu->gpu_sim_cycle);
       // the evicted block may have wrong chip id when advanced L2 hashing  is
       // used, so set the right chip address from the original mf
       wb->set_chip(mf->get_tlx_addr().chip);
@@ -1330,7 +1375,11 @@ enum cache_request_status data_cache::wr_miss_wa_fetch_on_write(
         m_tag_array->access(block_addr, time, cache_index, wb, evicted, mf);
     assert(status != HIT);
     cache_block_t *block = m_tag_array->get_block(cache_index);
+    if (!block->is_modified_line()) {
+      m_tag_array->inc_dirty();
+    }
     block->set_status(MODIFIED, mf->get_access_sector_mask());
+    block->set_byte_mask(mf);
     if (status == HIT_RESERVED)
       block->set_ignore_on_fill(true, mf->get_access_sector_mask());
 
@@ -1339,8 +1388,10 @@ enum cache_request_status data_cache::wr_miss_wa_fetch_on_write(
       // (already modified lower level)
       if (wb && (m_config.m_write_policy != WRITE_THROUGH)) {
         mem_fetch *wb = m_memfetch_creator->alloc(
-            evicted.m_block_addr, m_wrbk_type, evicted.m_modified_size, true,
-            m_gpu->gpu_tot_sim_cycle + m_gpu->gpu_sim_cycle);
+        evicted.m_block_addr,m_wrbk_type,
+        mf->get_access_warp_mask(), evicted.m_byte_mask,
+        evicted.m_sector_mask, evicted.m_modified_size,
+        true, m_gpu->gpu_tot_sim_cycle + m_gpu->gpu_sim_cycle);
         // the evicted block may have wrong chip id when advanced L2 hashing  is
         // used, so set the right chip address from the original mf
         wb->set_chip(mf->get_tlx_addr().chip);
@@ -1401,6 +1452,7 @@ enum cache_request_status data_cache::wr_miss_wa_fetch_on_write(
 
     cache_block_t *block = m_tag_array->get_block(cache_index);
     block->set_modified_on_fill(true, mf->get_access_sector_mask());
+    block->set_byte_mask_on_fill(true);
 
     events.push_back(cache_event(WRITE_ALLOCATE_SENT));
 
@@ -1409,8 +1461,10 @@ enum cache_request_status data_cache::wr_miss_wa_fetch_on_write(
       // (already modified lower level)
       if (wb && (m_config.m_write_policy != WRITE_THROUGH)) {
         mem_fetch *wb = m_memfetch_creator->alloc(
-            evicted.m_block_addr, m_wrbk_type, evicted.m_modified_size, true,
-            m_gpu->gpu_tot_sim_cycle + m_gpu->gpu_sim_cycle);
+        evicted.m_block_addr,m_wrbk_type,
+        mf->get_access_warp_mask(), evicted.m_byte_mask,
+        evicted.m_sector_mask, evicted.m_modified_size,
+        true, m_gpu->gpu_tot_sim_cycle + m_gpu->gpu_sim_cycle);
         // the evicted block may have wrong chip id when advanced L2 hashing  is
         // used, so set the right chip address from the original mf
         wb->set_chip(mf->get_tlx_addr().chip);
@@ -1428,16 +1482,39 @@ enum cache_request_status data_cache::wr_miss_wa_lazy_fetch_on_read(
     new_addr_type addr, unsigned cache_index, mem_fetch *mf, unsigned time,
     std::list<cache_event> &events, enum cache_request_status status) {
   new_addr_type block_addr = m_config.block_addr(addr);
+  new_addr_type mshr_addr = m_config.mshr_addr(mf->get_addr());
 
   // if the request writes to the whole cache line/sector, then, write and set
   // cache line Modified. and no need to send read request to memory or reserve
   // mshr
 
-  if (miss_queue_full(0)) {
-    m_stats.inc_fail_stats(mf->get_access_type(), MISS_QUEUE_FULL);
-    return RESERVATION_FAIL;  // cannot handle request this cycle
+  // Write allocate, maximum 2 requests (write miss, write back request)
+  // Conservatively ensure the worst-case request can be handled this
+  // cycle
+  if (m_config.m_write_policy == WRITE_THROUGH) {
+    bool mshr_hit = m_mshrs.probe(mshr_addr);
+    bool mshr_avail = !m_mshrs.full(mshr_addr);
+    if (miss_queue_full(1) ||
+        (!(mshr_hit && mshr_avail) &&
+         !(!mshr_hit && mshr_avail &&
+           (m_miss_queue.size() < m_config.m_miss_queue_size)))) {
+      // check what is the exactly the failure reason
+      if (miss_queue_full(1))
+        m_stats.inc_fail_stats(mf->get_access_type(), MISS_QUEUE_FULL);
+      else if (mshr_hit && !mshr_avail)
+        m_stats.inc_fail_stats(mf->get_access_type(), MSHR_MERGE_ENRTY_FAIL);
+      else if (!mshr_hit && !mshr_avail)
+        m_stats.inc_fail_stats(mf->get_access_type(), MSHR_ENRTY_FAIL);
+      else
+        assert(0);
+
+      return RESERVATION_FAIL;
+    }
+
+    send_write_request(mf, cache_event(WRITE_REQUEST_SENT), time, events);
   }
 
+
   bool wb = false;
   evicted_block_info evicted;
 
@@ -1445,11 +1522,15 @@ enum cache_request_status data_cache::wr_miss_wa_lazy_fetch_on_read(
       m_tag_array->access(block_addr, time, cache_index, wb, evicted, mf);
   assert(m_status != HIT);
   cache_block_t *block = m_tag_array->get_block(cache_index);
+  if (!block->is_modified_line()) {
+    m_tag_array->inc_dirty();
+  }
+  block->set_status(MODIFIED, mf->get_access_sector_mask());
+  block->set_byte_mask(mf);
   if (m_status == HIT_RESERVED) {
     block->set_ignore_on_fill(true, mf->get_access_sector_mask());
     block->set_modified_on_fill(true, mf->get_access_sector_mask());
-  } else {
-    block->set_status(MODIFIED, mf->get_access_sector_mask());
+    block->set_byte_mask_on_fill(true);
   }
 
   if (mf->get_access_byte_mask().count() == m_config.get_atom_sz()) {
@@ -1465,8 +1546,10 @@ enum cache_request_status data_cache::wr_miss_wa_lazy_fetch_on_read(
     // (already modified lower level)
     if (wb && (m_config.m_write_policy != WRITE_THROUGH)) {
       mem_fetch *wb = m_memfetch_creator->alloc(
-          evicted.m_block_addr, m_wrbk_type, evicted.m_modified_size, true,
-          m_gpu->gpu_tot_sim_cycle + m_gpu->gpu_sim_cycle);
+        evicted.m_block_addr,m_wrbk_type,
+        mf->get_access_warp_mask(), evicted.m_byte_mask,
+        evicted.m_sector_mask, evicted.m_modified_size,
+        true, m_gpu->gpu_tot_sim_cycle + m_gpu->gpu_sim_cycle);
       // the evicted block may have wrong chip id when advanced L2 hashing  is
       // used, so set the right chip address from the original mf
       wb->set_chip(mf->get_tlx_addr().chip);
@@ -1509,8 +1592,12 @@ enum cache_request_status data_cache::rd_hit_base(
   if (mf->isatomic()) {
     assert(mf->get_access_type() == GLOBAL_ACC_R);
     cache_block_t *block = m_tag_array->get_block(cache_index);
+    if (!block->is_modified_line()) {
+      m_tag_array->inc_dirty();
+    }
     block->set_status(MODIFIED,
-                      mf->get_access_sector_mask());  // mark line as dirty
+                      mf->get_access_sector_mask());  // mark line as 
+    block->set_byte_mask(mf);
   }
   return HIT;
 }
@@ -1541,8 +1628,10 @@ enum cache_request_status data_cache::rd_miss_base(
     // (already modified lower level)
     if (wb && (m_config.m_write_policy != WRITE_THROUGH)) {
       mem_fetch *wb = m_memfetch_creator->alloc(
-          evicted.m_block_addr, m_wrbk_type, evicted.m_modified_size, true,
-          m_gpu->gpu_tot_sim_cycle + m_gpu->gpu_sim_cycle);
+        evicted.m_block_addr,m_wrbk_type,
+        mf->get_access_warp_mask(), evicted.m_byte_mask,
+        evicted.m_sector_mask, evicted.m_modified_size,
+        true, m_gpu->gpu_tot_sim_cycle + m_gpu->gpu_sim_cycle);
       // the evicted block may have wrong chip id when advanced L2 hashing  is
       // used, so set the right chip address from the original mf
       wb->set_chip(mf->get_tlx_addr().chip);
@@ -1565,7 +1654,7 @@ enum cache_request_status read_only_cache::access(
   new_addr_type block_addr = m_config.block_addr(addr);
   unsigned cache_index = (unsigned)-1;
   enum cache_request_status status =
-      m_tag_array->probe(block_addr, cache_index, mf);
+      m_tag_array->probe(block_addr, cache_index, mf, mf->is_write());
   enum cache_request_status cache_status = RESERVATION_FAIL;
 
   if (status == HIT) {
@@ -1652,7 +1741,7 @@ enum cache_request_status data_cache::access(new_addr_type addr, mem_fetch *mf,
   new_addr_type block_addr = m_config.block_addr(addr);
   unsigned cache_index = (unsigned)-1;
   enum cache_request_status probe_status =
-      m_tag_array->probe(block_addr, cache_index, mf, true);
+      m_tag_array->probe(block_addr, cache_index, mf, mf->is_write(), true);
   enum cache_request_status access_status =
       process_tag_probe(wr, probe_status, addr, cache_index, mf, time, events);
   m_stats.inc_stats(mf->get_access_type(),