X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/f233a6d6c7d459205695d95e840063beba932147..6c686f5c734739033f848b8009c9b825b7aa9c1d:/src/mc/RegionSnapshot.cpp

diff --git a/src/mc/RegionSnapshot.cpp b/src/mc/RegionSnapshot.cpp
index 4a6e63f573..6d50ef1873 100644
--- a/src/mc/RegionSnapshot.cpp
+++ b/src/mc/RegionSnapshot.cpp
@@ -4,6 +4,8 @@
 /* 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 <sys/mman.h>
+
 #include "mc/mc.h"
 #include "mc_snapshot.h"
 #include "RegionSnapshot.hpp"
@@ -18,21 +20,62 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_RegionSnaphot, mc,
 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 "?";
+  }
+}
+
+void data_deleter::operator()(void* p) const
+{
+  switch(type_) {
+  case Free:
+    free(p);
+    break;
+  case Munmap:
+    munmap(p, size_);
+    break;
+  }
+}
+
 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,
+  simgrid::mc::RegionSnapshot::flat_data_ptr data;
+  if (!_sg_mc_ksm)
+    data = simgrid::mc::RegionSnapshot::flat_data_ptr((char*) malloc(size));
+  else {
+    char* ptr = (char*) mmap(nullptr, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_POPULATE, -1, 0);
+    if (ptr == MAP_FAILED)
+      throw std::bad_alloc();
+    simgrid::mc::data_deleter deleter(
+      simgrid::mc::data_deleter::Munmap, size);
+    data = simgrid::mc::RegionSnapshot::flat_data_ptr(ptr, deleter);
+  }
+  mc_model_checker->process().read_bytes(data.get(), size,
     remote(permanent_addr),
     simgrid::mc::ProcessIndexDisabled);
+  if (_sg_mc_ksm)
+    // Mark the region as mergeable *after* we have written into it.
+    // There no point to let KSM do the hard work before that.
+    madvise(data.get(), size, MADV_MERGEABLE);
 
   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);
+  XBT_DEBUG("New region : type : %s, data : %p (real addr %p), size : %zu",
+            to_cstr(region_type), region.flat_data(), permanent_addr, size);
   return std::move(region);
 }
 
@@ -44,28 +87,45 @@ RegionSnapshot dense_region(
  * @param size         Size of the data*
  */
 RegionSnapshot region(
-  RegionType type, void *start_addr, void* permanent_addr, size_t size)
+  RegionType type, void *start_addr, void* permanent_addr, size_t size,
+  RegionSnapshot const* ref_region)
 {
   if (_sg_mc_sparse_checkpoint) {
-    return sparse_region(type, start_addr, permanent_addr, size);
+    return sparse_region(type, start_addr, permanent_addr, size, ref_region);
   } 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)
+  void *start_addr, void* permanent_addr, size_t size,
+  RegionSnapshot const* ref_region)
 {
   simgrid::mc::Process* process = &mc_model_checker->process();
 
+  bool use_soft_dirty = _sg_mc_sparse_checkpoint && _sg_mc_soft_dirty
+    && ref_region != nullptr
+    && ref_region->storage_type() == simgrid::mc::StorageType::Chunked;
+
   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);
 
-  simgrid::mc::PerPageCopy page_data(mc_model_checker->page_store(), *process,
-      permanent_addr, page_count);
+  std::vector<std::uint64_t> pagemap;
+  const size_t* ref_page_numbers = nullptr;
+  if (use_soft_dirty) {
+    pagemap.resize(page_count);
+    process->read_pagemap(pagemap.data(),
+      mc_page_number(nullptr, permanent_addr), page_count);
+    ref_page_numbers = ref_region->page_data().pagenos();
+  }
+
+  simgrid::mc::PerPageCopy page_data(
+    mc_model_checker->page_store(), *process, permanent_addr, page_count,
+    ref_page_numbers,
+    use_soft_dirty ? pagemap.data() : nullptr);
 
   simgrid::mc::RegionSnapshot region(
     region_type, start_addr, permanent_addr, size);