#include <sys/mman.h>
#include <unistd.h>
+#include "src/internal_config.h"
#include "src/xbt/memory_map.hpp"
-#include "private.h"
#include "private.hpp"
+#include "smpi_process.hpp"
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_memory, smpi, "Memory layout support for SMPI");
-int smpi_loaded_page = -1;
-char* smpi_start_data_exe = nullptr;
-int smpi_size_data_exe = 0;
+int smpi_loaded_page = -1;
+char* smpi_data_exe_start = nullptr;
+int smpi_data_exe_size = 0;
int smpi_privatize_global_variables;
+static char* smpi_data_exe_copy;
+
+// We keep a copy of all the privatization regions: We can then delete everything easily by iterating over this
+// collection and nothing can be leaked. We could also iterate over all actors but we would have to be diligent when two
+// actors use the same privatization region (so, smart pointers would have to be used etc.)
+static std::set<smpi_privatization_region_t> smpi_privatization_regions;
static const int PROT_RWX = (PROT_READ | PROT_WRITE | PROT_EXEC);
static const int PROT_RW = (PROT_READ | PROT_WRITE );
// File backed RW entry:
if (i->pathname == full_name && (i->prot & PROT_RWX) == PROT_RW) {
- smpi_start_data_exe = (char*) i->start_addr;
- smpi_size_data_exe = i->end_addr - i->start_addr;
+ smpi_data_exe_start = (char*)i->start_addr;
+ smpi_data_exe_size = i->end_addr - i->start_addr;
++i;
/* 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. */
- if (i != map.end() && i->pathname.empty() && (i->prot & PROT_RWX) == PROT_RW
- && (char*)i->start_addr == smpi_start_data_exe + smpi_size_data_exe) {
- smpi_size_data_exe = (char*)i->end_addr - smpi_start_data_exe;
+ 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) {
+ smpi_data_exe_size = (char*)i->end_addr - smpi_data_exe_start;
}
return;
}
}
#endif
-#if defined(__has_feature)
-#define HAS_FEATURE(x) __has_feature(x)
-#else
-#define HAS_FEATURE(x) 0
-#endif
-#if HAS_FEATURE(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
+#if HAVE_SANITIZE_ADDRESS
#include <sanitizer/asan_interface.h>
-static void* safe_memcpy(void* dest, void* src, size_t n)
+static void* asan_safe_memcpy(void* dest, void* src, size_t n)
{
char* psrc = static_cast<char*>(src);
char* pdest = static_cast<char*>(dest);
return dest;
}
#else
-#define 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_really_switch_data_segment(int dest)
{
- if(smpi_size_data_exe == 0)//no need to switch
+ if (smpi_data_exe_size == 0) // no need to switch
return;
#if HAVE_PRIVATIZATION
- if(smpi_loaded_page==-1){//initial switch, do the copy from the real page here
- for (int i=0; i< smpi_process_count(); i++){
- safe_memcpy(smpi_privatization_regions[i].address, TOPAGE(smpi_start_data_exe), smpi_size_data_exe);
- }
- }
-
// FIXME, cross-process support (mmap across process when necessary)
- int current = smpi_privatization_regions[dest].file_descriptor;
+ simgrid::smpi::Process* process = smpi_process_remote(dest);
+ int current = process->privatized_region()->file_descriptor;
XBT_DEBUG("Switching data frame to the one of process %d", dest);
void* tmp =
- mmap(TOPAGE(smpi_start_data_exe), smpi_size_data_exe, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, current, 0);
- if (tmp != TOPAGE(smpi_start_data_exe))
+ mmap(TOPAGE(smpi_data_exe_start), smpi_data_exe_size, PROT_READ | PROT_WRITE, 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 = dest;
#endif
return buffer_path.compare(0, std::string::npos, file, buffer_path.length()) == 0;
}
-void smpi_initialize_global_memory_segments()
+// TODO: cheinrich: The behavior changed; this now only makes a backup of the
+// data segment. I think the function should be renamed.
+void smpi_backup_global_memory_segment()
{
-
#if HAVE_PRIVATIZATION
smpi_get_executable_global_size();
- XBT_DEBUG ("bss+data segment found : size %d starting at %p", smpi_size_data_exe, smpi_start_data_exe );
+ XBT_DEBUG("bss+data segment found : size %d starting at %p", smpi_data_exe_size, smpi_data_exe_start);
- if (smpi_size_data_exe == 0){//no need to switch
+ if (smpi_data_exe_size == 0) { // no need to do anything as global variables don't exist
smpi_privatize_global_variables=false;
return;
}
- smpi_privatization_regions = static_cast<smpi_privatization_region_t>(
- xbt_malloc(smpi_process_count() * sizeof(struct s_smpi_privatization_region)));
-
- for (int i=0; i< smpi_process_count(); i++){
- // create SIMIX_process_count() mappings of this size with the same data inside
- 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\
+ smpi_data_exe_copy = (char*)malloc(smpi_data_exe_size);
+ // Make a copy of the data segment. This clean copy is retained over the whole runtime
+ // of the simulation and can be used to initialize a dynamically added, new process.
+ asan_safe_memcpy(smpi_data_exe_copy, TOPAGE(smpi_data_exe_start), smpi_data_exe_size);
+#else /* ! HAVE_PRIVATIZATION */
+ smpi_privatize_global_variables = false;
+ xbt_die("You are trying to use privatization on a system that does not support it. Don't.");
+ return;
+#endif
+}
+
+// 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. \
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));
+ strerror(errno));
}
+ xbt_die("Impossible to create temporary file for memory mapping: %s", strerror(errno));
+ }
- status = ftruncate(file_descriptor, smpi_size_data_exe);
- if (status)
- xbt_die("Impossible to set the size of the temporary file for memory mapping");
+ 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_size_data_exe, PROT_READ | PROT_WRITE, MAP_SHARED, file_descriptor, 0);
- if (address == MAP_FAILED)
- xbt_die("Couldn't find a free region for memory mapping");
+ /* Ask for a free region */
+ address = mmap(nullptr, smpi_data_exe_size, PROT_READ | PROT_WRITE, 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");
+ status = shm_unlink(path);
+ if (status)
+ xbt_die("Impossible to unlink temporary file for memory mapping");
- // initialize the values
- safe_memcpy(address, TOPAGE(smpi_start_data_exe), smpi_size_data_exe);
+ // initialize the values
+ asan_safe_memcpy(address, smpi_data_exe_copy, smpi_data_exe_size);
- // store the address of the mapping for further switches
- smpi_privatization_regions[i].file_descriptor = file_descriptor;
- smpi_privatization_regions[i].address = address;
- }
-#else /* ! HAVE_PRIVATIZATION */
- smpi_privatize_global_variables = false;
- xbt_die("You are trying to use privatization on a system that does not support it. Don't.");
- return;
-#endif
+ // store the address of the mapping for further switches
+ smpi_privatization_region_t tmp =
+ static_cast<smpi_privatization_region_t>(new struct s_smpi_privatization_region_t);
+
+ tmp->file_descriptor = file_descriptor;
+ tmp->address = address;
+ smpi_privatization_regions.insert(tmp);
+
+ return tmp;
}
void smpi_destroy_global_memory_segments(){
- if (smpi_size_data_exe == 0)//no need to switch
+ if (smpi_data_exe_size == 0) // no need to switch
return;
#if HAVE_PRIVATIZATION
- for (int i=0; i< smpi_process_count(); i++) {
- if (munmap(smpi_privatization_regions[i].address, smpi_size_data_exe) < 0)
- XBT_WARN("Unmapping of fd %d failed: %s", smpi_privatization_regions[i].file_descriptor, strerror(errno));
- close(smpi_privatization_regions[i].file_descriptor);
+ for (auto& it : smpi_privatization_regions) {
+ if (munmap(it->address, smpi_data_exe_size) < 0)
+ XBT_WARN("Unmapping of fd %d failed: %s", it->file_descriptor, strerror(errno));
+ close(it->file_descriptor);
}
- xbt_free(smpi_privatization_regions);
#endif
}
