X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/96cedde3cdbc0b8ffc3f096a1b65d021b0226f99..12623e213e87741da4f0e42917f31b51cf9db0f1:/src/smpi/internals/smpi_memory.cpp diff --git a/src/smpi/internals/smpi_memory.cpp b/src/smpi/internals/smpi_memory.cpp index 14214de4a4..723c5df5e3 100644 --- a/src/smpi/internals/smpi_memory.cpp +++ b/src/smpi/internals/smpi_memory.cpp @@ -1,4 +1,4 @@ -/* Copyright (c) 2015-2019. The SimGrid Team. All rights reserved. */ +/* Copyright (c) 2015-2020. 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. */ @@ -55,10 +55,10 @@ void smpi_prepare_global_memory_segment() static void smpi_get_executable_global_size() { - char buffer[PATH_MAX]; - char* full_name = realpath(xbt_binary_name, buffer); - if (full_name == nullptr) - xbt_die("Could not resolve binary file name"); + char* buffer = realpath(simgrid::xbt::binary_name.c_str(), nullptr); + xbt_assert(buffer != nullptr, "Could not resolve real path of binary file '%s'", simgrid::xbt::binary_name.c_str()); + std::string full_name = buffer; + free(buffer); std::vector map = simgrid::xbt::get_memory_map(getpid()); for (auto i = map.begin(); i != map.end() ; ++i) { @@ -72,14 +72,15 @@ static void smpi_get_executable_global_size() /* Here we are making the assumption that a suitable empty region following the rw- area is the end of the data segment. It would be better to check with the size of the data segment. */ - ++i; - if (i != map.end() && i->pathname.empty() && (i->prot & PROT_RWX) == PROT_RW && - (char*)i->start_addr == smpi_data_exe_start + smpi_data_exe_size) { - // Only count this region if it was not already present in the initial map. - auto found = std::find_if(begin(initial_vm_map), end(initial_vm_map), - [&i](const simgrid::xbt::VmMap& m) { return m.start_addr == i->start_addr; }); - if (found == end(initial_vm_map)) - smpi_data_exe_size = (char*)i->end_addr - smpi_data_exe_start; + auto j = i + 1; + if (j != map.end() && j->pathname.empty() && (j->prot & PROT_RWX) == PROT_RW && + (char*)j->start_addr == smpi_data_exe_start + smpi_data_exe_size) { + // Only count the portion of this region not present in the initial map. + auto found = std::find_if(initial_vm_map.begin(), initial_vm_map.end(), [&j](const simgrid::xbt::VmMap& m) { + return j->start_addr <= m.start_addr && m.start_addr < j->end_addr; + }); + auto end_addr = (found == initial_vm_map.end() ? j->end_addr : found->start_addr); + smpi_data_exe_size = (char*)end_addr - smpi_data_exe_start; } return; } @@ -107,47 +108,99 @@ static void* asan_safe_memcpy(void* dest, void* src, size_t n) return dest; } #else -#define asan_safe_memcpy(dest, src, n) memcpy(dest, src, n) +#define asan_safe_memcpy(dest, src, n) memcpy((dest), (src), (n)) #endif -/** Map a given SMPI privatization segment (make a SMPI process active) */ -void smpi_switch_data_segment(simgrid::s4u::ActorPtr actor) +/** + * @brief Uses shm_open to get a temporary shm, and returns its file descriptor. + */ +int smpi_temp_shm_get() { - if (smpi_loaded_page == actor->get_pid()) // no need to switch, we've already loaded the one we want - return; + constexpr unsigned VAL_MASK = 0xffffffffUL; + static unsigned prev_val = VAL_MASK; + char shmname[32]; // cannot be longer than PSHMNAMLEN = 31 on macOS (shm_open raises ENAMETOOLONG otherwise) + int fd; + + for (unsigned i = (prev_val + 1) & VAL_MASK; i != prev_val; i = (i + 1) & VAL_MASK) { + snprintf(shmname, sizeof(shmname), "/smpi-buffer-%016x", i); + fd = shm_open(shmname, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR); + if (fd != -1 || errno != EEXIST) { + prev_val = i; + break; + } + } + if (fd < 0) { + if (errno == EMFILE) { + xbt_die("Impossible to create temporary file for memory mapping: %s\n\ +The shm_open() system call failed with the EMFILE error code (too many files). \n\n\ +This means that you reached the system limits concerning the amount of files per process. \ +This is not a surprise if you are trying to virtualize many processes on top of SMPI. \ +Don't panic -- you should simply increase your system limits and try again. \n\n\ +First, check what your limits are:\n\ + cat /proc/sys/fs/file-max # Gives you the system-wide limit\n\ + ulimit -Hn # Gives you the per process hard limit\n\ + ulimit -Sn # Gives you the per process soft limit\n\ + cat /proc/self/limits # Displays any per-process limitation (including the one given above)\n\n\ +If one of these values is less than the amount of MPI processes that you try to run, then you got the explanation of this error. \ +Ask the Internet about tutorials on how to increase the files limit such as: https://rtcamp.com/tutorials/linux/increase-open-files-limit/", + strerror(errno)); + } + xbt_die("Impossible to create temporary file for memory mapping. shm_open: %s", strerror(errno)); + } + XBT_DEBUG("Got temporary shm %s (fd = %d)", shmname, fd); + if (shm_unlink(shmname) < 0) + XBT_WARN("Could not early unlink %s. shm_unlink: %s", shmname, strerror(errno)); + return fd; +} - // So the job: - smpi_really_switch_data_segment(actor); +/** + * @brief Mmap a region of size bytes from temporary shm with file descriptor fd. + */ +void* smpi_temp_shm_mmap(int fd, size_t size) +{ + struct stat st; + if (fstat(fd, &st) != 0) + xbt_die("Could not stat fd %d: %s", fd, strerror(errno)); + if (static_cast(size) > st.st_size && ftruncate(fd, static_cast(size)) != 0) + xbt_die("Could not truncate fd %d to %zu: %s", fd, size, strerror(errno)); + void* mem = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + if (mem == MAP_FAILED) { + xbt_die("Failed to map fd %d with size %zu: %s\n" + "If you are running a lot of ranks, you may be exceeding the amount of mappings allowed per process.\n" + "On Linux systems, change this value with sudo sysctl -w vm.max_map_count=newvalue (default value: 65536)\n" + "Please see " + "https://simgrid.org/doc/latest/Configuring_SimGrid.html#configuring-the-user-code-virtualization for more " + "information.", + fd, size, strerror(errno)); + } + return mem; } -/** Map a given SMPI privatization segment (make a SMPI process active) even if SMPI thinks it is already active +/** Map a given SMPI privatization segment (make an SMPI process active) * * When doing a state restoration, the state of the restored variables might not be consistent with the state of the * virtual memory. In this case, we to change the data segment. */ -void smpi_really_switch_data_segment(simgrid::s4u::ActorPtr actor) +void smpi_switch_data_segment(simgrid::s4u::ActorPtr actor) { + if (smpi_loaded_page == actor->get_pid()) // no need to switch, we've already loaded the one we want + return; + if (smpi_data_exe_size == 0) // no need to switch return; #if HAVE_PRIVATIZATION // FIXME, cross-process support (mmap across process when necessary) XBT_DEBUG("Switching data frame to the one of process %ld", actor->get_pid()); - simgrid::smpi::ActorExt* process = smpi_process_remote(actor); + const simgrid::smpi::ActorExt* process = smpi_process_remote(actor); int current = process->privatized_region()->file_descriptor; - void* tmp = mmap(TOPAGE(smpi_data_exe_start), smpi_data_exe_size, PROT_RW, MAP_FIXED | MAP_SHARED, current, 0); + const void* tmp = mmap(TOPAGE(smpi_data_exe_start), smpi_data_exe_size, PROT_RW, MAP_FIXED | MAP_SHARED, current, 0); if (tmp != TOPAGE(smpi_data_exe_start)) xbt_die("Couldn't map the new region (errno %d): %s", errno, strerror(errno)); smpi_loaded_page = actor->get_pid(); #endif } -int smpi_is_privatization_file(char* file) -{ - const std::string buffer_path("/dev/shm/my-buffer-"); - return buffer_path.compare(0, std::string::npos, file, buffer_path.length()) == 0; -} - /** * @brief Makes a backup of the segment in memory that stores the global variables of a process. * This backup is then used to initialize the global variables for every single @@ -179,46 +232,10 @@ void smpi_backup_global_memory_segment() // Initializes the memory mapping for a single process and returns the privatization region smpi_privatization_region_t smpi_init_global_memory_segment_process() { - int file_descriptor; - void* address = nullptr; - char path[24]; - int status; - - do { - snprintf(path, sizeof(path), "/smpi-buffer-%06x", rand() % 0xffffffU); - file_descriptor = shm_open(path, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR); - } while (file_descriptor == -1 && errno == EEXIST); - if (file_descriptor < 0) { - if (errno == EMFILE) { - xbt_die("Impossible to create temporary file for memory mapping: %s\n\ -The open() system call failed with the EMFILE error code (too many files). \n\n\ -This means that you reached the system limits concerning the amount of files per process. \ -This is not a surprise if you are trying to virtualize many processes on top of SMPI. \ -Don't panic -- you should simply increase your system limits and try again. \n\n\ -First, check what your limits are:\n\ - cat /proc/sys/fs/file-max # Gives you the system-wide limit\n\ - ulimit -Hn # Gives you the per process hard limit\n\ - ulimit -Sn # Gives you the per process soft limit\n\ - cat /proc/self/limits # Displays any per-process limitation (including the one given above)\n\n\ -If one of these values is less than the amount of MPI processes that you try to run, then you got the explanation of this error. \ -Ask the Internet about tutorials on how to increase the files limit such as: https://rtcamp.com/tutorials/linux/increase-open-files-limit/", - strerror(errno)); - } - xbt_die("Impossible to create temporary file for memory mapping: %s", strerror(errno)); - } + int file_descriptor = smpi_temp_shm_get(); - status = ftruncate(file_descriptor, smpi_data_exe_size); - if (status) - xbt_die("Impossible to set the size of the temporary file for memory mapping"); - - /* Ask for a free region */ - address = mmap(nullptr, smpi_data_exe_size, PROT_RW, MAP_SHARED, file_descriptor, 0); - if (address == MAP_FAILED) - xbt_die("Couldn't find a free region for memory mapping"); - - status = shm_unlink(path); - if (status) - xbt_die("Impossible to unlink temporary file for memory mapping"); + // ask for a free region + void* address = smpi_temp_shm_mmap(file_descriptor, smpi_data_exe_size); // initialize the values asan_safe_memcpy(address, smpi_data_exe_copy, smpi_data_exe_size); @@ -243,40 +260,39 @@ void smpi_destroy_global_memory_segments(){ #endif } -static int sendbuffer_size = 0; -static char* sendbuffer = nullptr; -static int recvbuffer_size = 0; -static char* recvbuffer = nullptr; +static std::vector sendbuffer; +static std::vector recvbuffer; //allocate a single buffer for all sends, growing it if needed -void* smpi_get_tmp_sendbuffer(int size) +unsigned char* smpi_get_tmp_sendbuffer(size_t size) { if (not smpi_process()->replaying()) - return xbt_malloc(size); - if (sendbuffer_size(xbt_realloc(sendbuffer,size)); - sendbuffer_size=size; - } - return sendbuffer; + return new unsigned char[size]; + // FIXME: a resize() may invalidate a previous pointer. Maybe we need to handle a queue of buffers with a reference + // counter. The same holds for smpi_get_tmp_recvbuffer. + if (sendbuffer.size() < size) + sendbuffer.resize(size); + return sendbuffer.data(); } //allocate a single buffer for all recv -void* smpi_get_tmp_recvbuffer(int size){ +unsigned char* smpi_get_tmp_recvbuffer(size_t size) +{ if (not smpi_process()->replaying()) - return xbt_malloc(size); - if (recvbuffer_size(xbt_realloc(recvbuffer,size)); - recvbuffer_size=size; - } - return recvbuffer; + return new unsigned char[size]; + if (recvbuffer.size() < size) + recvbuffer.resize(size); + return recvbuffer.data(); } -void smpi_free_tmp_buffer(void* buf){ +void smpi_free_tmp_buffer(const unsigned char* buf) +{ if (not smpi_process()->replaying()) - xbt_free(buf); + delete[] buf; } -void smpi_free_replay_tmp_buffers(){ - xbt_free(sendbuffer); - xbt_free(recvbuffer); +void smpi_free_replay_tmp_buffers() +{ + std::vector().swap(sendbuffer); + std::vector().swap(recvbuffer); }