/* 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>
#include "mc/mc.h"
#include "src/mc/ChunkedData.hpp"
#include "src/mc/RegionSnapshot.hpp"
-extern "C" {
-
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_RegionSnaphot, mc,
"Logging specific to region snapshots");
-}
-
namespace simgrid {
namespace mc {
}
}
-void data_deleter::operator()(void* p) const
+Buffer::Buffer(std::size_t size, Type type) : size_(size), type_(type)
{
switch(type_) {
- case Free:
- free(p);
+ case Type::Malloc:
+ data_ = ::malloc(size_);
break;
- case Munmap:
- munmap(p, size_);
+ 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:
+ std::free(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)
{
- 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);
- }
+ // 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);
+
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.
+ // Trying to merge them before is useless/counterproductive.
madvise(data.get(), size, MADV_MERGEABLE);
simgrid::mc::RegionSnapshot region(
region.flat_data(std::move(data));
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);
+ to_cstr(region_type), region.flat_data().get(), permanent_addr, size);
+ return region;
}
/** @brief Take a snapshot of a given region
* @param size Size of the data*
*/
RegionSnapshot region(
- RegionType type, void *start_addr, void* permanent_addr, size_t size,
- RegionSnapshot const* ref_region)
+ RegionType type, void *start_addr, void* permanent_addr, size_t size)
{
- if (_sg_mc_sparse_checkpoint) {
- return sparse_region(type, start_addr, permanent_addr, size, ref_region);
- } else {
+ if (_sg_mc_sparse_checkpoint)
+ return sparse_region(type, start_addr, permanent_addr, size);
+ 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,
- RegionSnapshot const* ref_region)
+ void *start_addr, void* permanent_addr, size_t size)
{
simgrid::mc::Process* process = &mc_model_checker->process();
- assert(process != NULL);
-
- bool use_soft_dirty = _sg_mc_sparse_checkpoint && _sg_mc_soft_dirty
- && ref_region != nullptr
- && ref_region->storage_type() == simgrid::mc::StorageType::Chunked;
+ 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);
-
- 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();
- }
+ size_t page_count = simgrid::mc::mmu::chunkCount(size);
simgrid::mc::ChunkedData page_data(
- mc_model_checker->page_store(), *process, permanent_addr, page_count,
- ref_page_numbers,
- use_soft_dirty ? pagemap.data() : nullptr);
+ mc_model_checker->page_store(), *process, 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;
}
}
