On Wed, 26 Jun 2024 16:51:42 +0200 David Marchand <david.march...@redhat.com> wrote:
> On a ARM system with only 2MB hugepages configured, EAL emits an error > log with allocations larger than 512MB. > > Example with testpmd: > $ dpdk-testpmd --in-memory --no-pci --log-level=*:debug -- -i > ... > EAL: In-memory mode enabled, hugepages of size 33554432 bytes will be > allocated anonymously > EAL: No free 32768 kB hugepages reported on node 0 > EAL: In-memory mode enabled, hugepages of size 65536 bytes will be > allocated anonymously > EAL: No free 64 kB hugepages reported on node 0 > EAL: In-memory mode enabled, hugepages of size 1073741824 bytes will be > allocated anonymously > EAL: No free 1048576 kB hugepages reported on node 0 > ... > EAL: Detected memory type: socket_id:0 hugepage_sz:1073741824 > EAL: Detected memory type: socket_id:0 hugepage_sz:33554432 > EAL: Detected memory type: socket_id:0 hugepage_sz:2097152 > EAL: Detected memory type: socket_id:0 hugepage_sz:65536 > EAL: Creating 2 segment lists: n_segs:32 socket_id:0 > hugepage_sz:1073741824 > ... > EAL: Creating 2 segment lists: n_segs:1024 socket_id:0 > hugepage_sz:33554432 > ... > EAL: Creating 4 segment lists: n_segs:8192 socket_id:0 > hugepage_sz:2097152 > ... > EAL: Creating 4 segment lists: n_segs:8192 socket_id:0 > hugepage_sz:65536 > ... > EAL: Trying to obtain current memory policy. > EAL: Setting policy MPOL_PREFERRED for socket 0 > EAL: alloc_seg(): mmap() failed: Cannot allocate memory > EAL: Ask a virtual area of 0x40000000 bytes > EAL: Virtual area found at 0x140000000 (size = 0x40000000) > EAL: attempted to allocate 2 segments, but only 0 were allocated > EAL: Restoring previous memory policy: 4 > EAL: Trying to obtain current memory policy. > EAL: Setting policy MPOL_PREFERRED for socket 0 > EAL: eal_memalloc_alloc_seg_bulk(): couldn't find suitable memseg_list > EAL: Restoring previous memory policy: 4 > EAL: Trying to obtain current memory policy. > EAL: Setting policy MPOL_PREFERRED for socket 0 > EAL: Restoring previous memory policy: 4 > EAL: request: mp_malloc_sync > EAL: No shared files mode enabled, IPC is disabled > EAL: Heap on socket 0 was expanded by 1064MB > ... > > The reason is that the memzone allocation (~1GB large) would require > 17017 (32kB) segments. However, as displayed in the early logs, a 32kB > memory segment list can only host 8192 segments (controlled by the build > option RTE_MAX_MEMSEG_PER_LIST). > > This log message is misleading as there is no issue in the end: the > allocation succeeded with 2MB hugepages. > > Fixes: 582bed1e1d1d ("mem: support mapping hugepages at runtime") > Cc: sta...@dpdk.org > > Signed-off-by: David Marchand <david.march...@redhat.com> > --- Acked-by: Stephen Hemminger <step...@networkplumber.org>