Unaccepted memory bitmap is allocated during decompression stage and handed over to main kernel image via boot_params. The bitmap is used to track if memory has been accepted. Reserve unaccepted memory bitmap has to prevent reallocating memory for other means. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> --- arch/x86/kernel/e820.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index bc0657f0deed..dc9048e2d421 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -1290,6 +1290,16 @@ void __init e820__memory_setup(void) pr_info("BIOS-provided physical RAM map:\n"); e820__print_table(who); + + /* Mark unaccepted memory bitmap reserved */ + if (boot_params.unaccepted_memory) { + unsigned long size; + + /* One bit per 2MB */ + size = DIV_ROUND_UP(e820__end_of_ram_pfn() * PAGE_SIZE, + PMD_SIZE * BITS_PER_BYTE); + memblock_reserve(boot_params.unaccepted_memory, size); + } } void __init e820__memblock_setup(void) -- 2.34.1