X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/0ef1caaf350ac106b3431e8afb4246aace1b44d2..1847d1441271d076b3de449c8853031ea208ce8f:/src/mc/PageStore.cpp diff --git a/src/mc/PageStore.cpp b/src/mc/PageStore.cpp index 2935004ed1..a2e49930c9 100644 --- a/src/mc/PageStore.cpp +++ b/src/mc/PageStore.cpp @@ -1,35 +1,33 @@ -/* Copyright (c) 2014. The SimGrid Team. +/* Copyright (c) 2015-2017. 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 // memcpy, memcmp #include -#include // memcpy, memcp #include +#ifdef __FreeBSD__ +# define MAP_POPULATE MAP_PREFAULT_READ +#endif -#include - -#include - -#include "PageStore.hpp" +#include "xbt/base.h" +#include "xbt/log.h" +#include "xbt/sysdep.h" -#ifdef MC_PAGE_STORE_MD4 -#include -#endif +#include "src/internal_config.h" -#include "mc_mmu.h" +#include "src/mc/PageStore.hpp" -extern "C" { +#include "src/mc/mc_mmu.h" -XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_page_snapshot, mc, - "Logging specific to mc_page_snapshot"); +XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_page_snapshot, mc, "Logging specific to mc_page_snapshot"); namespace simgrid { namespace mc { -/** @brief Compte a hash for the given memory page +/** @brief Compute a hash for the given memory page * * The page is used before inserting the page in the page store * in order to find duplicate of this page in the page store. @@ -37,44 +35,28 @@ namespace mc { * @param data Memory page * @return hash off the page */ -static inline __attribute__ ((always_inline)) -PageStore::hash_type mc_hash_page(const void* data) +static XBT_ALWAYS_INLINE PageStore::hash_type mc_hash_page(const void* data) { -#ifdef MC_PAGE_STORE_MD4 - boost::array result; - md4_ctx context; - md4_init(&context); - md4_update(&context, xbt_pagesize, (const uint8_t*) data); - md4_digest(&context, MD4_DIGEST_SIZE, (uint8_t*) &(result[0])); - return result; -#else - const uint64_t* values = (const uint64_t*) data; - size_t n = xbt_pagesize / sizeof(uint64_t); + const std::uint64_t* values = (const uint64_t*) data; + std::size_t n = xbt_pagesize / sizeof(uint64_t); // This djb2: - uint64_t hash = 5381; - for (size_t i=0; i!=n; ++i) { + std::uint64_t hash = 5381; + for (std::size_t i = 0; i != n; ++i) hash = ((hash << 5) + hash) + values[i]; - } return hash; -#endif } // ***** snapshot_page_manager -PageStore::PageStore(size_t size) : - memory_(NULL), capacity_(0), top_index_(0) +PageStore::PageStore(size_t size) : memory_(nullptr), capacity_(size), top_index_(0) { - // Using mmap in order to be able to expand the region - // by relocating it somewhere else in the virtual memory - // space: - void * memory = ::mmap(NULL, size << xbt_pagebits, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_POPULATE, -1, 0); - if (memory==MAP_FAILED) { + // Using mmap in order to be able to expand the region by relocating it somewhere else in the virtual memory space: + void* memory = ::mmap(nullptr, size << xbt_pagebits, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_POPULATE, -1, 0); + if (memory == MAP_FAILED) xbt_die("Could not mmap initial snapshot pages."); - } this->top_index_ = 0; - this->capacity_ = size; this->memory_ = memory; this->page_counts_.resize(size); } @@ -84,17 +66,50 @@ PageStore::~PageStore() ::munmap(this->memory_, this->capacity_ << xbt_pagebits); } -void PageStore::resize(size_t size) +void PageStore::resize(std::size_t size) { size_t old_bytesize = this->capacity_ << xbt_pagebits; size_t new_bytesize = size << xbt_pagebits; + void *new_memory; // Expand the memory region by moving it into another // virtual memory address if necessary: - void* new_memory = mremap(this->memory_, old_bytesize, new_bytesize, MREMAP_MAYMOVE); - if (new_memory == MAP_FAILED) { +#if HAVE_MREMAP + new_memory = mremap(this->memory_, old_bytesize, new_bytesize, MREMAP_MAYMOVE); + if (new_memory == MAP_FAILED) xbt_die("Could not mremap snapshot pages."); +#else + if (new_bytesize > old_bytesize) { + // Grow: first try to add new space after current map + new_memory = mmap((char *)this->memory_ + old_bytesize, + new_bytesize-old_bytesize, + PROT_READ|PROT_WRITE, + MAP_PRIVATE|MAP_ANONYMOUS|MAP_POPULATE, + -1, 0); + if (new_memory == MAP_FAILED) + xbt_die("Could not mremap snapshot pages."); + // Check if expanding worked + if (new_memory != (char *)this->memory_ + old_bytesize) { + // New memory segment could not be put at the end of this->memory_, + // so cancel this one and try to rellocate everything and copy data + munmap(new_memory, new_bytesize-old_bytesize); + new_memory = mmap(nullptr, + new_bytesize, + PROT_READ|PROT_WRITE, + MAP_PRIVATE|MAP_ANONYMOUS|MAP_POPULATE, + -1, 0); + if (new_memory == MAP_FAILED) + xbt_die("Could not mremap snapshot pages."); + memcpy(new_memory, this->memory_, old_bytesize); + munmap(this->memory_, old_bytesize); + } + } + else { + // We don't have functions to shrink a mapping, so leave memory as + // it is for now + new_memory = this->memory_; } +#endif this->capacity_ = size; this->memory_ = new_memory; @@ -105,15 +120,14 @@ void PageStore::resize(size_t size) * * @return index of the free page */ -size_t PageStore::alloc_page() +std::size_t PageStore::alloc_page() { if (this->free_pages_.empty()) { // Expand the region: - if (this->top_index_ == this->capacity_) { + if (this->top_index_ == this->capacity_) // All the pages are allocated, we need add more pages: this->resize(2 * this->capacity_); - } // Use a page from the top: return this->top_index_++; @@ -124,71 +138,47 @@ size_t PageStore::alloc_page() size_t res = this->free_pages_[this->free_pages_.size() - 1]; this->free_pages_.pop_back(); return res; - } } -void PageStore::remove_page(size_t pageno) +void PageStore::remove_page(std::size_t pageno) { this->free_pages_.push_back(pageno); const void* page = this->get_page(pageno); hash_type hash = mc_hash_page(page); -#ifdef MC_PAGE_STORE_MD4 - this->hash_index_.erase(hash); -#else this->hash_index_[hash].erase(pageno); -#endif } /** Store a page in memory */ -size_t PageStore::store_page(void* page) +std::size_t PageStore::store_page(void* page) { xbt_assert(top_index_ <= this->capacity_, "top_index is not consistent"); - // First, we check if a page with the same content is already in the page - // store: + // First, we check if a page with the same content is already in the page store: // 1. compute the hash of the page; // 2. find pages with the same hash using `hash_index_`; // 3. find a page with the same content. hash_type hash = mc_hash_page(page); -#ifdef MC_PAGE_STORE_MD4 - s_mc_pages_store::pages_map_type::const_iterator i = - this->hash_index_.find(hash); - if (i!=this->hash_index_.cend()) { - // If a page with the same content is already in the page store it is - // reused and its reference count is incremented. - size_t pageno = i->second; - page_counts_[pageno]++; - return pageno; - } -#else // Try to find a duplicate in set of pages with the same hash: page_set_type& page_set = this->hash_index_[hash]; - BOOST_FOREACH (size_t pageno, page_set) { + for (size_t const& pageno : page_set) { const void* snapshot_page = this->get_page(pageno); if (memcmp(page, snapshot_page, xbt_pagesize) == 0) { - // If a page with the same content is already in the page store it is - // reused and its reference count is incremented. + // If a page with the same content is already in the page store it's reused and its refcount is incremented. page_counts_[pageno]++; return pageno; } } -#endif - // Otherwise, a new page is allocated in the page store and the content - // of the page is `memcpy()`-ed to this new page. - size_t pageno = alloc_page(); + // Otherwise, a new page is allocated in the page store and the content of the page is `memcpy()`-ed to this new page. + std::size_t pageno = alloc_page(); xbt_assert(this->page_counts_[pageno]==0, "Allocated page is already used"); void* snapshot_page = (void*) this->get_page(pageno); memcpy(snapshot_page, page, xbt_pagesize); -#ifdef MC_PAGE_STORE_MD4 - this->hash_index_[hash] = pageno; -#else page_set.insert(pageno); -#endif page_counts_[pageno]++; return pageno; } @@ -198,38 +188,37 @@ size_t PageStore::store_page(void* page) #ifdef SIMGRID_TEST -#include -#include -#include +#include +#include + #include #include #include -#include "mc/PageStore.hpp" +#include "src/mc/PageStore.hpp" static int value = 0; -static void new_content(void* data, size_t size) +static void new_content(void* data, std::size_t size) { - memset(data, ++value, size); + ::memset(data, ++value, size); } static void* getpage() { - return mmap(NULL, getpagesize(), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); + return mmap(nullptr, getpagesize(), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); } -extern "C" { - XBT_TEST_SUITE("mc_page_store", "Page store"); XBT_TEST_UNIT("base", test_mc_page_store, "Test adding/removing pages in the store") { + using simgrid::mc::PageStore; + xbt_test_add("Init"); - size_t pagesize = (size_t) getpagesize(); - std::unique_ptr store - = std::unique_ptr(new simgrid::mc::PageStore(500)); + std::size_t pagesize = (size_t) getpagesize(); + std::unique_ptr store = std::unique_ptr(new simgrid::mc::PageStore(500)); void* data = getpage(); xbt_test_assert(store->size()==0, "Bad size"); @@ -238,7 +227,7 @@ XBT_TEST_UNIT("base", test_mc_page_store, "Test adding/removing pages in the sto size_t pageno1 = store->store_page(data); xbt_test_assert(store->get_ref(pageno1)==1, "Bad refcount"); const void* copy = store->get_page(pageno1); - xbt_test_assert(memcmp(data, copy, pagesize)==0, "Page data should be the same"); + xbt_test_assert(::memcmp(data, copy, pagesize)==0, "Page data should be the same"); xbt_test_assert(store->size()==1, "Bad size"); xbt_test_add("Store the same page again"); @@ -268,8 +257,4 @@ XBT_TEST_UNIT("base", test_mc_page_store, "Test adding/removing pages in the sto xbt_test_assert(store->size()==2, "Bad size"); } -} - #endif /* SIMGRID_TEST */ - -}