sudo sh -c 'echo 1 > /proc/sys/vm/nr_hugepages'
\endcode
+Note that at least one huge page is required for smpirun, but you can set
+an higher number of huge pages in nr_hugepages (e.g. "echo 27").
Then, you can pass the option --cfg=smpi/shared-malloc-hugepage:/home/huge
to smpirun.
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, "/");