diff --git a/hw/pc.c b/hw/pc.c
index 4f6a522..10446ba 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -45,6 +45,11 @@
 #include "loader.h"
 #include "elf.h"
 #include "multiboot.h"
+#include "kvm.h"
+
+#ifndef _WIN32
+#include <sys/mman.h>
+#endif
 
 /* output Bochs bios info messages */
 //#define DEBUG_BIOS
@@ -63,10 +68,19 @@
 
 #define MAX_IDE_BUS 2
 
+#define MAX_MEMORY_ENTRIES 10
+
+typedef struct MemoryEntry {
+    ram_addr_t addr;
+    ram_addr_t size;
+} MemoryEntry;
+
 static FDCtrl *floppy_controller;
 static RTCState *rtc_state;
 static PITState *pit;
 static PCII440FXState *i440fx_state;
+static int num_memory_entries;
+static MemoryEntry memory_entries[MAX_MEMORY_ENTRIES];
 
 #define E820_NR_ENTRIES		16
 
@@ -782,6 +796,27 @@ static CPUState *pc_new_cpu(const char *cpu_model)
     return env;
 }
 
+static void add_mem_entry(ram_addr_t addr, ram_addr_t size)
+{
+    memory_entries[num_memory_entries].addr = addr;
+    memory_entries[num_memory_entries].size = size;
+    num_memory_entries++;
+}
+
+static void pc_reset_ram(void *opaque)
+{
+    int i;
+
+    for (i = 0; i < num_memory_entries; i++) {
+#ifndef _WIN32
+        if (!kvm_enabled() || kvm_has_sync_mmu()) {
+            madvise(qemu_get_ram_ptr(memory_entries[i].addr),
+                    memory_entries[i].size, MADV_DONTNEED);
+        }
+#endif
+    }
+}
+
 /* PC hardware initialisation */
 static void pc_init1(ram_addr_t ram_size,
                      const char *boot_device,
@@ -835,6 +870,7 @@ static void pc_init1(ram_addr_t ram_size,
     /* allocate RAM */
     ram_addr = qemu_ram_alloc(0xa0000);
     cpu_register_physical_memory(0, 0xa0000, ram_addr);
+    add_mem_entry(ram_addr, 0xa0000);
 
     /* Allocate, even though we won't register, so we don't break the
      * phys_ram_base + PA assumption. This range includes vga (0xa0000 - 0xc0000),
@@ -845,6 +881,7 @@ static void pc_init1(ram_addr_t ram_size,
     cpu_register_physical_memory(0x100000,
                  below_4g_mem_size - 0x100000,
                  ram_addr);
+    add_mem_entry(ram_addr, below_4g_mem_size - 0x100000);
 
     /* above 4giga memory allocation */
     if (above_4g_mem_size > 0) {
@@ -855,6 +892,7 @@ static void pc_init1(ram_addr_t ram_size,
         cpu_register_physical_memory(0x100000000ULL,
                                      above_4g_mem_size,
                                      ram_addr);
+        add_mem_entry(ram_addr, above_4g_mem_size);
 #endif
     }
 
@@ -1050,6 +1088,8 @@ static void pc_init1(ram_addr_t ram_size,
             pci_create_simple(pci_bus, -1, "lsi53c895a");
         }
     }
+
+    qemu_register_reset(pc_reset_ram, NULL);
 }
 
 static void pc_init_pci(ram_addr_t ram_size,