• Dan Williams's avatar
    libnvdimm, pfn: fix 'npfns' vs section alignment · d5483fed
    Dan Williams authored
    Fix failures to create namespaces due to the vmem_altmap not advertising
    enough free space to store the memmap.
    
     WARNING: CPU: 15 PID: 8022 at arch/x86/mm/init_64.c:656 arch_add_memory+0xde/0xf0
     [..]
     Call Trace:
      dump_stack+0x63/0x83
      __warn+0xcb/0xf0
      warn_slowpath_null+0x1d/0x20
      arch_add_memory+0xde/0xf0
      devm_memremap_pages+0x244/0x440
      pmem_attach_disk+0x37e/0x490 [nd_pmem]
      nd_pmem_probe+0x7e/0xa0 [nd_pmem]
      nvdimm_bus_probe+0x71/0x120 [libnvdimm]
      driver_probe_device+0x2bb/0x460
      bind_store+0x114/0x160
      drv_attr_store+0x25/0x30
    
    In commit 658922e5 "libnvdimm, pfn: fix memmap reservation sizing"
    we arranged for the capacity to be allocated, but failed to also update
    the 'npfns' parameter. This leads to cases where there is enough
    capacity reserved to hold all the allocated sections, but
    vmemmap_populate_hugepages() still encounters -ENOMEM from
    altmap_alloc_block_buf().
    
    This fix is a stop-gap until we can teach the core memory hotplug
    implementation to permit sub-section hotplug.
    
    Cc: <stable@vger.kernel.org>
    Fixes: 658922e5 ("libnvdimm, pfn: fix memmap reservation sizing")
    Reported-by: default avatarAnisha Allada <anisha.allada@intel.com>
    Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
    d5483fed
pfn_devs.c 17.5 KB