From 8c81c1d04e8d20b08f122a12ce090b4f926adb4c Mon Sep 17 00:00:00 2001 From: Mahmoud Date: Wed, 22 Aug 2018 10:19:52 -0400 Subject: adding lazy-fetch-on-read and invalidate operation to cache --- src/gpgpu-sim/gpu-cache.cc | 110 ++++++++++++++++++++++++++------------------- 1 file changed, 63 insertions(+), 47 deletions(-) (limited to 'src/gpgpu-sim/gpu-cache.cc') diff --git a/src/gpgpu-sim/gpu-cache.cc b/src/gpgpu-sim/gpu-cache.cc index 75ec00a..9d81de9 100644 --- a/src/gpgpu-sim/gpu-cache.cc +++ b/src/gpgpu-sim/gpu-cache.cc @@ -382,6 +382,8 @@ void tag_array::fill( unsigned index, unsigned time, mem_fetch* mf) m_lines[index]->fill(time, mf->get_access_sector_mask()); } + +//TODO: we need write back the flushed data to the upper level void tag_array::flush() { for (unsigned i=0; i < m_config.get_num_lines(); i++) @@ -391,6 +393,13 @@ void tag_array::flush() } } +void tag_array::invalidate() +{ + for (unsigned i=0; i < m_config.get_num_lines(); i++) + for(unsigned j=0; j < SECTOR_CHUNCK_SIZE; j++) + m_lines[i]->set_status(INVALID, mem_access_sector_mask_t().set(j)) ; +} + float tag_array::windowed_miss_rate( ) const { unsigned n_access = m_access - m_prev_snapshot_access; @@ -1162,52 +1171,7 @@ data_cache::wr_miss_wa_fetch_on_write( new_addr_type addr, unsigned time, std::list &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 - } - - bool wb = false; - evicted_block_info evicted; - - cache_request_status m_status = 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); - block->set_status(MODIFIED, mf->get_access_sector_mask()); - 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()); - } - - if(mf->get_access_byte_mask().count() == m_config.get_atom_sz()) - { - block->set_m_readable(true, mf->get_access_sector_mask()); - } else - { - block->set_m_readable(false, mf->get_access_sector_mask()); - } - - if( m_status != RESERVATION_FAIL ){ - // If evicted block is modified and not a write-through - // (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); - send_write_request(wb, cache_event(WRITE_BACK_REQUEST_SENT, evicted), time, events); - } - return MISS; - } - return RESERVATION_FAIL; - - /*new_addr_type block_addr = m_config.block_addr(addr); + new_addr_type block_addr = m_config.block_addr(addr); new_addr_type mshr_addr = m_config.mshr_addr(mf->get_addr()); if(mf->get_access_byte_mask().count() == m_config.get_atom_sz()) @@ -1316,7 +1280,59 @@ data_cache::wr_miss_wa_fetch_on_write( new_addr_type addr, return MISS; } return RESERVATION_FAIL; - }*/ + } +} + +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 &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 + } + + bool wb = false; + evicted_block_info evicted; + + cache_request_status m_status = 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); + block->set_status(MODIFIED, mf->get_access_sector_mask()); + 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()); + } + + if(mf->get_access_byte_mask().count() == m_config.get_atom_sz()) + { + block->set_m_readable(true, mf->get_access_sector_mask()); + } else + { + block->set_m_readable(false, mf->get_access_sector_mask()); + } + + if( m_status != RESERVATION_FAIL ){ + // If evicted block is modified and not a write-through + // (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); + send_write_request(wb, cache_event(WRITE_BACK_REQUEST_SENT, evicted), time, events); + } + return MISS; + } + return RESERVATION_FAIL; } /// No write-allocate miss: Simply send write request to lower level memory -- cgit v1.3