X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=page_cache.c;h=5f8578736e041b32774ad23aa69d31b9e30194a1;hb=b8dc35b2526278296390fffa80b5c82573ed178a;hp=b033681a937b61a51ffe0e0d4464f27112f8cd73;hpb=f53f3d0a00b6df39ce8dfca942608e5b6a9a4f71;p=mirror_qemu.git

diff --git a/page_cache.c b/page_cache.c
index b033681a93..5f8578736e 100644
--- a/page_cache.c
+++ b/page_cache.c
@@ -12,17 +12,10 @@
  *
  */
 
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <strings.h>
-#include <string.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <stdbool.h>
-#include <glib.h>
+#include "qemu/osdep.h"
 
 #include "qemu-common.h"
+#include "qemu/host-utils.h"
 #include "migration/page_cache.h"
 
 #ifdef DEBUG_CACHE
@@ -33,6 +26,9 @@
     do { } while (0)
 #endif
 
+/* the page in cache will not be replaced in two cycles */
+#define CACHED_PAGE_LIFETIME 2
+
 typedef struct CacheItem CacheItem;
 
 struct CacheItem {
@@ -109,28 +105,14 @@ void cache_fini(PageCache *cache)
 
     g_free(cache->page_cache);
     cache->page_cache = NULL;
+    g_free(cache);
 }
 
 static size_t cache_get_cache_pos(const PageCache *cache,
                                   uint64_t address)
 {
-    size_t pos;
-
     g_assert(cache->max_num_items);
-    pos = (address / cache->page_size) & (cache->max_num_items - 1);
-    return pos;
-}
-
-bool cache_is_cached(const PageCache *cache, uint64_t addr)
-{
-    size_t pos;
-
-    g_assert(cache);
-    g_assert(cache->page_cache);
-
-    pos = cache_get_cache_pos(cache, addr);
-
-    return (cache->page_cache[pos].it_addr == addr);
+    return (address / cache->page_size) & (cache->max_num_items - 1);
 }
 
 static CacheItem *cache_get_by_addr(const PageCache *cache, uint64_t addr)
@@ -150,17 +132,35 @@ uint8_t *get_cached_data(const PageCache *cache, uint64_t addr)
     return cache_get_by_addr(cache, addr)->it_data;
 }
 
-int cache_insert(PageCache *cache, uint64_t addr, const uint8_t *pdata)
+bool cache_is_cached(const PageCache *cache, uint64_t addr,
+                     uint64_t current_age)
 {
+    CacheItem *it;
 
-    CacheItem *it = NULL;
+    it = cache_get_by_addr(cache, addr);
 
-    g_assert(cache);
-    g_assert(cache->page_cache);
+    if (it->it_addr == addr) {
+        /* update the it_age when the cache hit */
+        it->it_age = current_age;
+        return true;
+    }
+    return false;
+}
+
+int cache_insert(PageCache *cache, uint64_t addr, const uint8_t *pdata,
+                 uint64_t current_age)
+{
+
+    CacheItem *it;
 
     /* actual update of entry */
     it = cache_get_by_addr(cache, addr);
 
+    if (it->it_data && it->it_addr != addr &&
+        it->it_age + CACHED_PAGE_LIFETIME > current_age) {
+        /* the cache page is fresh, don't replace it */
+        return -1;
+    }
     /* allocate page */
     if (!it->it_data) {
         it->it_data = g_try_malloc(cache->page_size);
@@ -173,7 +173,7 @@ int cache_insert(PageCache *cache, uint64_t addr, const uint8_t *pdata)
 
     memcpy(it->it_data, pdata, cache->page_size);
 
-    it->it_age = ++cache->max_item_age;
+    it->it_age = current_age;
     it->it_addr = addr;
 
     return 0;