1 /* Copyright (c) 2007-2015. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
10 #include "src/mc/mc_snapshot.h"
12 #include "src/mc/ChunkedData.hpp"
13 #include "src/mc/RegionSnapshot.hpp"
17 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_RegionSnaphot, mc,
18 "Logging specific to region snapshots");
26 const char* to_cstr(RegionType region)
29 case RegionType::Unknown:
31 case RegionType::Heap:
33 case RegionType::Data:
40 void data_deleter::operator()(void* p) const
52 RegionSnapshot dense_region(
53 RegionType region_type,
54 void *start_addr, void* permanent_addr, size_t size)
56 simgrid::mc::RegionSnapshot::flat_data_ptr data;
58 data = simgrid::mc::RegionSnapshot::flat_data_ptr((char*) malloc(size));
60 char* ptr = (char*) mmap(nullptr, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_POPULATE, -1, 0);
61 if (ptr == MAP_FAILED)
62 throw std::bad_alloc();
63 simgrid::mc::data_deleter deleter(
64 simgrid::mc::data_deleter::Munmap, size);
65 data = simgrid::mc::RegionSnapshot::flat_data_ptr(ptr, deleter);
67 mc_model_checker->process().read_bytes(data.get(), size,
68 remote(permanent_addr),
69 simgrid::mc::ProcessIndexDisabled);
71 // Mark the region as mergeable *after* we have written into it.
72 // There no point to let KSM do the hard work before that.
73 madvise(data.get(), size, MADV_MERGEABLE);
75 simgrid::mc::RegionSnapshot region(
76 region_type, start_addr, permanent_addr, size);
77 region.flat_data(std::move(data));
79 XBT_DEBUG("New region : type : %s, data : %p (real addr %p), size : %zu",
80 to_cstr(region_type), region.flat_data(), permanent_addr, size);
81 return std::move(region);
84 /** @brief Take a snapshot of a given region
87 * @param start_addr Address of the region in the simulated process
88 * @param permanent_addr Permanent address of this data (for privatized variables, this is the virtual address of the privatized mapping)
89 * @param size Size of the data*
91 RegionSnapshot region(
92 RegionType type, void *start_addr, void* permanent_addr, size_t size,
93 RegionSnapshot const* ref_region)
95 if (_sg_mc_sparse_checkpoint) {
96 return sparse_region(type, start_addr, permanent_addr, size, ref_region);
98 return dense_region(type, start_addr, permanent_addr, size);
102 RegionSnapshot sparse_region(RegionType region_type,
103 void *start_addr, void* permanent_addr, size_t size,
104 RegionSnapshot const* ref_region)
106 simgrid::mc::Process* process = &mc_model_checker->process();
108 bool use_soft_dirty = _sg_mc_sparse_checkpoint && _sg_mc_soft_dirty
109 && ref_region != nullptr
110 && ref_region->storage_type() == simgrid::mc::StorageType::Chunked;
112 xbt_assert((((uintptr_t)start_addr) & (xbt_pagesize-1)) == 0,
113 "Not at the beginning of a page");
114 xbt_assert((((uintptr_t)permanent_addr) & (xbt_pagesize-1)) == 0,
115 "Not at the beginning of a page");
116 size_t page_count = mc_page_count(size);
118 std::vector<std::uint64_t> pagemap;
119 const size_t* ref_page_numbers = nullptr;
120 if (use_soft_dirty) {
121 pagemap.resize(page_count);
122 process->read_pagemap(pagemap.data(),
123 mc_page_number(nullptr, permanent_addr), page_count);
124 ref_page_numbers = ref_region->page_data().pagenos();
127 simgrid::mc::ChunkedData page_data(
128 mc_model_checker->page_store(), *process, permanent_addr, page_count,
130 use_soft_dirty ? pagemap.data() : nullptr);
132 simgrid::mc::RegionSnapshot region(
133 region_type, start_addr, permanent_addr, size);
134 region.page_data(std::move(page_data));
135 return std::move(region);