[mc] Rename PerPageCopy to ChunkedData (and move in its own files)

[simgrid.git] / src / mc / RegionSnapshot.cpp

diff --git a/src/mc/RegionSnapshot.cpp b/src/mc/RegionSnapshot.cpp
index 634aadc..74986e1 100644 (file)
--- a/src/mc/RegionSnapshot.cpp
+++ b/src/mc/RegionSnapshot.cpp
@@ -8,7 +8,9 @@
 
 #include "mc/mc.h"
 #include "mc_snapshot.h"
-#include "RegionSnapshot.hpp"
+
+#include <mc/ChunkedData.hpp>
+#include <mc/RegionSnapshot.hpp>
 
 extern "C" {
 
@@ -51,10 +53,24 @@ RegionSnapshot dense_region(
   RegionType region_type,
   void *start_addr, void* permanent_addr, size_t size)
 {
-  simgrid::mc::RegionSnapshot::flat_data_ptr data((char*) malloc(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);
@@ -73,28 +89,45 @@ 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::ChunkedData 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);