Patchwork [4/4] page_cache: dup memory on insert

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Submitter Orit Wasserman
Date Feb. 25, 2013, 1:19 p.m.
Message ID <1361798382-6515-5-git-send-email-owasserm@redhat.com>
Download mbox | patch
Permalink /patch/222922/
State New
Headers show

Comments

Orit Wasserman - Feb. 25, 2013, 1:19 p.m.
From: Peter Lieven <pl@dlhnet.de>

The page cache frees all data on finish, on resize and
if there is collision on insert. So it should be the caches
responsibility to dup the data that is stored in the cache.

From: Peter Lieven <pl@kamp.de>

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
 arch_init.c                    | 3 +--
 include/migration/page_cache.h | 3 ++-
 page_cache.c                   | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

Patch

diff --git a/arch_init.c b/arch_init.c
index 8da868b..97bcc29 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -293,8 +293,7 @@  static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
 
     if (!cache_is_cached(XBZRLE.cache, current_addr)) {
         if (!last_stage) {
-            cache_insert(XBZRLE.cache, current_addr,
-                         g_memdup(current_data, TARGET_PAGE_SIZE));
+            cache_insert(XBZRLE.cache, current_addr, current_data);
         }
         acct_info.xbzrle_cache_miss++;
         return -1;
diff --git a/include/migration/page_cache.h b/include/migration/page_cache.h
index 3839ac7..87894fe 100644
--- a/include/migration/page_cache.h
+++ b/include/migration/page_cache.h
@@ -57,7 +57,8 @@  bool cache_is_cached(const PageCache *cache, uint64_t addr);
 uint8_t *get_cached_data(const PageCache *cache, uint64_t addr);
 
 /**
- * cache_insert: insert the page into the cache. the previous value will be overwritten
+ * cache_insert: insert the page into the cache. the page cache
+ * will dup the data on insert. the previous value will be overwritten
  *
  * @cache pointer to the PageCache struct
  * @addr: page address
diff --git a/page_cache.c b/page_cache.c
index 07da547..daac506 100644
--- a/page_cache.c
+++ b/page_cache.c
@@ -159,7 +159,7 @@  void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata)
         cache->num_items++;
     }
 
-    it->it_data = pdata;
+    it->it_data = g_memdup(pdata, cache->page_size);
     it->it_age = ++cache->max_item_age;
     it->it_addr = addr;
 }