X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/f233a6d6c7d459205695d95e840063beba932147..c9e3badfcca0d44e112171cefd237ed3f0ae01ca:/src/mc/RegionSnapshot.cpp

diff --git a/src/mc/RegionSnapshot.cpp b/src/mc/RegionSnapshot.cpp
index 4a6e63f573..4ebfbe1729 100644
--- a/src/mc/RegionSnapshot.cpp
+++ b/src/mc/RegionSnapshot.cpp
@@ -1,39 +1,112 @@
-/* Copyright (c) 2007-2015. The SimGrid Team.
+/* Copyright (c) 2007-2017. The SimGrid Team.
  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
+#include <cstdlib>
+
+#include <sys/mman.h>
+#ifdef __FreeBSD__
+# define MAP_POPULATE MAP_PREFAULT_READ
+#endif
+
 #include "mc/mc.h"
-#include "mc_snapshot.h"
-#include "RegionSnapshot.hpp"
+#include "src/mc/mc_snapshot.hpp"
 
-extern "C" {
+#include "src/mc/ChunkedData.hpp"
+#include "src/mc/RegionSnapshot.hpp"
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_RegionSnaphot, mc,
                                 "Logging specific to region snapshots");
 
-}
-
 namespace simgrid {
 namespace mc {
 
+static inline
+const char* to_cstr(RegionType region)
+{
+  switch (region) {
+  case RegionType::Unknown:
+    return "unknown";
+  case RegionType::Heap:
+    return "Heap";
+  case RegionType::Data:
+    return "Data";
+  default:
+    return "?";
+  }
+}
+
+Buffer::Buffer(std::size_t size, Type type) : size_(size), type_(type)
+{
+  switch(type_) {
+  case Type::Malloc:
+    data_ = ::operator new(size_);
+    break;
+  case Type::Mmap:
+    data_ = ::mmap(nullptr, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_POPULATE, -1, 0);
+    if (data_ == MAP_FAILED) {
+      data_ = nullptr;
+      size_ = 0;
+      type_ = Type::Malloc;
+      throw std::bad_alloc();
+    }
+    break;
+  default:
+    abort();
+  }
+}
+
+void Buffer::clear() noexcept
+{
+  switch(type_) {
+  case Type::Malloc:
+    ::operator delete(data_);
+    break;
+  case Type::Mmap:
+    if (munmap(data_, size_) != 0)
+      abort();
+    break;
+  default:
+    abort();
+  }
+  data_ = nullptr;
+  size_ = 0;
+  type_ = Type::Malloc;
+}
+
 RegionSnapshot dense_region(
   RegionType region_type,
   void *start_addr, void* permanent_addr, size_t size)
 {
-  std::vector<char> data(size);
-  mc_model_checker->process().read_bytes(data.data(), size,
+  // When KSM support is enables, we allocate memory using mmap:
+  // * we don't want to advise bits of the heap as mergable
+  // * mmap gives data aligned on page boundaries which is merge friendly
+  simgrid::mc::Buffer data;
+  if (_sg_mc_ksm)
+    data = Buffer::mmap(size);
+  else
+    data = Buffer::malloc(size);
+
+  mc_model_checker->process().read_bytes(data.get(), size,
     remote(permanent_addr),
     simgrid::mc::ProcessIndexDisabled);
 
+#ifdef __linux__
+  if (_sg_mc_ksm)
+    // Mark the region as mergeable *after* we have written into it.
+    // Trying to merge them before is useless/counterproductive.
+    madvise(data.get(), size, MADV_MERGEABLE);
+#endif
+
   simgrid::mc::RegionSnapshot region(
     region_type, start_addr, permanent_addr, size);
   region.flat_data(std::move(data));
 
-  XBT_DEBUG("New region : type : %d, data : %p (real addr %p), size : %zu",
-            region_type, region.flat_data().data(), permanent_addr, size);
-  return std::move(region);
+  XBT_DEBUG("New region : type : %s, data : %p (real addr %p), size : %zu",
+            to_cstr(region_type), region.flat_data().get(), permanent_addr, size);
+  return region;
 }
 
 /** @brief Take a snapshot of a given region
@@ -46,32 +119,32 @@ RegionSnapshot dense_region(
 RegionSnapshot region(
   RegionType type, void *start_addr, void* permanent_addr, size_t size)
 {
-  if (_sg_mc_sparse_checkpoint) {
+  if (_sg_mc_sparse_checkpoint)
     return sparse_region(type, start_addr, permanent_addr, size);
-  } else  {
+  else
     return dense_region(type, start_addr, permanent_addr, size);
-  }
 }
 
 RegionSnapshot sparse_region(RegionType region_type,
   void *start_addr, void* permanent_addr, size_t size)
 {
-  simgrid::mc::Process* process = &mc_model_checker->process();
+  simgrid::mc::RemoteClient* process = &mc_model_checker->process();
+  assert(process != nullptr);
 
   xbt_assert((((uintptr_t)start_addr) & (xbt_pagesize-1)) == 0,
     "Not at the beginning of a page");
   xbt_assert((((uintptr_t)permanent_addr) & (xbt_pagesize-1)) == 0,
     "Not at the beginning of a page");
-  size_t page_count = mc_page_count(size);
+  size_t page_count = simgrid::mc::mmu::chunkCount(size);
 
-  simgrid::mc::PerPageCopy page_data(mc_model_checker->page_store(), *process,
-      permanent_addr, page_count);
+  simgrid::mc::ChunkedData page_data(mc_model_checker->page_store(), *process, RemotePtr<void>(permanent_addr),
+                                     page_count);
 
   simgrid::mc::RegionSnapshot region(
     region_type, start_addr, permanent_addr, size);
   region.page_data(std::move(page_data));
-  return std::move(region);
+  return region;
 }
-  
+
 }
 }