From 72cfed41641bbea2ea3dc78958ed3b1e2c27bbf9 Mon Sep 17 00:00:00 2001
From: Steve Reinhardt <steve.reinhardt@amd.com>
Date: Sat, 26 Sep 2009 10:50:50 -0700
Subject: Force prefetches to check cache and MSHRs immediately prior to issue.
 This prevents redundant prefetches from being issued, solving the occasional
 'needsExclusive && !blk->isWritable()' assertion failure in cache_impl.hh
 that several people have run into. Eliminates "prefetch_cache_check_push"
 flag, neither setting of which really solved the problem.

---
 src/mem/cache/prefetch/base.cc | 16 ----------------
 src/mem/cache/prefetch/base.hh |  4 ----
 2 files changed, 20 deletions(-)

(limited to 'src/mem/cache/prefetch')

diff --git a/src/mem/cache/prefetch/base.cc b/src/mem/cache/prefetch/base.cc
index f0e244a09..ad7a0c882 100644
--- a/src/mem/cache/prefetch/base.cc
+++ b/src/mem/cache/prefetch/base.cc
@@ -45,7 +45,6 @@
 BasePrefetcher::BasePrefetcher(const BaseCacheParams *p)
     : size(p->prefetcher_size), pageStop(!p->prefetch_past_page),
       serialSquash(p->prefetch_serial_squash),
-      cacheCheckPush(p->prefetch_cache_check_push),
       onlyData(p->prefetch_data_accesses_only)
 {
 }
@@ -143,9 +142,6 @@ BasePrefetcher::getPacket()
     do {
         pkt = *pf.begin();
         pf.pop_front();
-        if (!cacheCheckPush) {
-            keep_trying = cache->inCache(pkt->getAddr());
-        }
 
         if (keep_trying) {
             DPRINTF(HWPrefetch, "addr 0x%x in cache, skipping\n",
@@ -226,18 +222,6 @@ BasePrefetcher::notify(PacketPtr &pkt, Tick time)
                     "inserting into prefetch queue with delay %d time %d\n",
                     addr, *delayIter, time);
 
-            // Check if it is already in the cache
-            if (cacheCheckPush && cache->inCache(addr)) {
-                DPRINTF(HWPrefetch, "Prefetch addr already in cache\n");
-                continue;
-            }
-
-            // Check if it is already in the miss_queue
-            if (cache->inMissQueue(addr)) {
-                DPRINTF(HWPrefetch, "Prefetch addr already in miss queue\n");
-                continue;
-            }
-
             // Check if it is already in the pf buffer
             if (inPrefetch(addr) != pf.end()) {
                 pfBufferHit++;
diff --git a/src/mem/cache/prefetch/base.hh b/src/mem/cache/prefetch/base.hh
index b5f33a455..e3c0cbf16 100644
--- a/src/mem/cache/prefetch/base.hh
+++ b/src/mem/cache/prefetch/base.hh
@@ -68,10 +68,6 @@ class BasePrefetcher
     /** Do we remove prefetches with later times than a new miss.*/
     bool serialSquash;
 
-    /** Do we check if it is in the cache when inserting into buffer,
-        or removing.*/
-    bool cacheCheckPush;
-
     /** Do we prefetch on only data reads, or on inst reads as well. */
     bool onlyData;
 
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