void* smpi_shared_malloc_partial(size_t size, size_t* shared_block_offsets, int nb_shared_blocks)
{
char *huge_page_mount_point = xbt_cfg_get_string("smpi/shared-malloc-hugepage");
- const bool use_huge_page = huge_page_mount_point[0] != '\0';
+ bool use_huge_page = huge_page_mount_point[0] != '\0';
+#ifndef MAP_HUGETLB /* If the system header don't define that mmap flag */
+ xbt_assert(not use_huge_page,
+ "Huge pages are not available on your system, you cannot use the smpi/shared-malloc-hugepage option.");
+ use_huge_page = 0;
+#endif
smpi_shared_malloc_blocksize = static_cast<unsigned long>(xbt_cfg_get_double("smpi/shared-malloc-blocksize"));
void *mem, *allocated_ptr;
size_t allocated_size;
xbt_assert(allocated_ptr != MAP_FAILED, "Failed to allocate %zuMiB of memory. Run \"sysctl vm.overcommit_memory=1\" as root "
"to allow big allocations.\n",
size >> 20);
-
if(use_huge_page)
mem = (void*)ALIGN_UP((uint64_t)allocated_ptr, HUGE_PAGE_SIZE);
else
XBT_DEBUG("global shared allocation. Blocksize %lu", smpi_shared_malloc_blocksize);
/* Create a fd to a new file on disk, make it smpi_shared_malloc_blocksize big, and unlink it.
* It still exists in memory but not in the file system (thus it cannot be leaked). */
- /* Create bogus file if not done already */
+ /* Create bogus file if not done already
+ * We need two different bogusfiles:
+ * smpi_shared_malloc_bogusfile_huge_page is used for calls to mmap *with* MAP_HUGETLB,
+ * smpi_shared_malloc_bogusfile is used for calls to mmap *without* MAP_HUGETLB.
+ * We cannot use a same file for the two type of calls, since the first one needs to be
+ * opened in a hugetlbfs mount point whereas the second needs to be a "classical" file. */
if(use_huge_page && smpi_shared_malloc_bogusfile_huge_page == -1) {
const char *const array[] = {huge_page_mount_point, "simgrid-shmalloc-XXXXXX", nullptr};
char *huge_page_filename = xbt_str_join_array(array, "/");
int mmap_base_flag = MAP_FIXED | MAP_SHARED | MAP_POPULATE;
int mmap_flag = mmap_base_flag;
int huge_fd = use_huge_page ? smpi_shared_malloc_bogusfile_huge_page : smpi_shared_malloc_bogusfile;
+#ifdef MAP_HUGETLB
if(use_huge_page)
mmap_flag |= MAP_HUGETLB;
+#endif
XBT_DEBUG("global shared allocation, begin mmap");