Just in case I need, let us say, 1.5 GB CONTIGUOUS memory zone, would it be fine to use something like this as GRUB config in Linux?
default_hugepagesz=2G hugepagesz=2G hugepages=4" On Wed, May 22, 2024 at 12:22 PM Antonio Di Bacco <[email protected]> wrote: > > That was really useful. Thx > > On Fri, May 10, 2024 at 5:07 PM Dmitry Kozlyuk <[email protected]> > wrote: > > > > 2024-05-10 11:33 (UTC+0200), Antonio Di Bacco: > > > I have 16 hugepages available per NUMA on a 4 NUMA system: > > > > > > [user@node-1 hugepages]$ cat > > > /sys/devices/system/node/*/hugepages/hugepages-1048576kB/free_hugepages > > > 16 > > > 16 > > > 16 > > > 16 > > > > > > Using the following program with dpdk 21.11, sometimes I can allocate > > > a few pages but most of the time I cannot. I tried also to remove > > > rtemap_* under /dev/hugepages. > > > rte_memzone_reserve_aligned is always supposed to use a new page? > > > > > > #include <stdio.h> > > > #include <rte_eal.h> > > > #include <rte_memzone.h> > > > > > > #include <rte_errno.h> > > > #include <unistd.h> > > > > > > int main(int argc, char **argv) > > > { > > > const struct rte_memzone *mz; > > > int ret; > > > printf("pid: %d\n", getpid()); > > > // Initialize EAL > > > ret = rte_eal_init(argc, argv); > > > if (ret < 0) { > > > fprintf(stderr, "Error with EAL initialization\n"); > > > return -1; > > > } > > > > > > for (int socket = 0; socket < 4; socket++) > > > { > > > for (int i = 0; i < 16; i++) > > > { > > > // Allocate memory using rte_memzone_reserve_aligned > > > char name[32]; > > > sprintf(name, "my_memzone%d-%d", i, socket); > > > mz = rte_memzone_reserve_aligned(name, 1ULL << 30, socket, > > > RTE_MEMZONE_IOVA_CONTIG, 1ULL << 30); > > > > > > if (mz == NULL) { > > > printf("errno %s\n", rte_strerror(rte_errno)); > > > fprintf(stderr, "Memory allocation failed\n"); > > > rte_eal_cleanup(); > > > return -1; > > > } > > > > > > printf("Memory allocated with name %s at socket %d physical > > > address: %p, addr %p addr64 %lx size: %zu\n", name, mz->socket_id, > > > (mz->iova), mz->addr, mz->addr_64, mz->len); > > > } > > > } > > > > > > // Clean up EAL > > > rte_eal_cleanup(); > > > return 0; > > > } > > > > Hi Antonio, > > > > Does it succeed without RTE_MEMZONE_IOVA_CONTIG? > > If so, does your system/app have ASLR enabled? > > > > When memzone size is 1G and hugepage size is 1G, > > two hugepages are required: one for the requested amount of memory, > > and one for memory allocator element header, > > which does not fit into the same page obviously. > > I suspect that two allocated hugepages get non-continuous IOVA > > and that's why the function fails. > > There are no useful logs in EAL to check the suspicion, > > but you can hack elem_check_phys_contig() in malloc_elem.c.
