On Wed, 11 May 2022 01:05:30 +0000 Zhou Guanghui <zhouguanghui1@xxxxxxxxxx> wrote: > During early boot, the number of memblocks may exceed 128(some memory > areas are not reported to the kernel due to test failures. As a result, > contiguous memory is divided into multiple parts for reporting). If > the size of the init memblock regions is exceeded before the array size > can be resized, the excess memory will be lost. > > ... > > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -89,6 +89,14 @@ config SPARSEMEM_VMEMMAP > pfn_to_page and page_to_pfn operations. This is the most > efficient option when sufficient kernel resources are available. > > +config MEMBLOCK_INIT_REGIONS > + int "Number of init memblock regions" > + range 128 1024 > + default 128 > + help > + The number of init memblock regions which used to track "memory" and > + "reserved" memblocks during early boot. > + > config HAVE_MEMBLOCK_PHYS_MAP > bool > > diff --git a/mm/memblock.c b/mm/memblock.c > index e4f03a6e8e56..6893d26b750e 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -22,7 +22,7 @@ > > #include "internal.h" > > -#define INIT_MEMBLOCK_REGIONS 128 > +#define INIT_MEMBLOCK_REGIONS CONFIG_MEMBLOCK_INIT_REGIONS Consistent naming would be nice - MEMBLOCK_INIT versus INIT_MEMBLOCK. Can we simply increase INIT_MEMBLOCK_REGIONS to 1024 and avoid the config option? It appears that the overhead from this would be 60kB or so. Or zero if CONFIG_ARCH_KEEP_MEMBLOCK and CONFIG_MEMORY_HOTPLUG are cooperating.
