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-rw-r--r--block/qcow2-cache.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/block/qcow2-cache.c b/block/qcow2-cache.c
index 53b8afc3d3..f63e7d8e70 100644
--- a/block/qcow2-cache.c
+++ b/block/qcow2-cache.c
@@ -22,8 +22,16 @@
* THE SOFTWARE.
*/
+/* Needed for CONFIG_MADVISE */
+#include "config-host.h"
+
+#if defined(CONFIG_MADVISE) || defined(CONFIG_POSIX_MADVISE)
+#include <sys/mman.h>
+#endif
+
#include "block/block_int.h"
#include "qemu-common.h"
+#include "qemu/osdep.h"
#include "qcow2.h"
#include "trace.h"
@@ -60,6 +68,22 @@ static inline int qcow2_cache_get_table_idx(BlockDriverState *bs,
return idx;
}
+static void qcow2_cache_table_release(BlockDriverState *bs, Qcow2Cache *c,
+ int i, int num_tables)
+{
+#if QEMU_MADV_DONTNEED != QEMU_MADV_INVALID
+ BDRVQcowState *s = bs->opaque;
+ void *t = qcow2_cache_get_table_addr(bs, c, i);
+ int align = getpagesize();
+ size_t mem_size = (size_t) s->cluster_size * num_tables;
+ size_t offset = QEMU_ALIGN_UP((uintptr_t) t, align) - (uintptr_t) t;
+ size_t length = QEMU_ALIGN_DOWN(mem_size - offset, align);
+ if (length > 0) {
+ qemu_madvise((uint8_t *) t + offset, length, QEMU_MADV_DONTNEED);
+ }
+#endif
+}
+
Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables)
{
BDRVQcowState *s = bs->opaque;
@@ -237,6 +261,8 @@ int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c)
c->entries[i].lru_counter = 0;
}
+ qcow2_cache_table_release(bs, c, 0, c->size);
+
c->lru_counter = 0;
return 0;