On 1/11/22 03:33, Kirill A. Shutemov wrote:
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.
I'm having a hard time parsing that changelog, especially the second
paragraph. Could you give it another shot?
+ /* 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);
+ }
Is it OK that the size of the bitmap is inferred from
e820__end_of_ram_pfn()? Is this OK in the presence of mem= and other
things that muck with the e820?
