On Sun, 2020-10-25 at 12:15 +0200, Mike Rapoport wrote:
> + if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
> + unsigned long addr = (unsigned
> long)page_address(page);
> + int ret;
> +
> + if (enable)
> + ret = set_direct_map_default_noflush(page);
> + else
> + ret = set_direct_map_invalid_noflush(page);
> +
> + if (WARN_ON(ret))
> + return;
> +
> + flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
> + } else {
> + debug_pagealloc_map_pages(page, 1, enable);
> + }
Looking at the arm side again, I think this might actually introduce a
regression for the arm/hibernate/DEBUG_PAGEALLOC combo.
Unlike __kernel_map_pages(), it looks like arm's cpa will always bail
in the set_direct_map_() functions if rodata_full is false. So if
rodata_full was disabled but debug page alloc is on, then this would
now skip remapping the pages. I guess the significance depends on
whether hibernate could actually try to save any DEBUG_PAGEALLOC
unmapped pages. Looks like it to me though.
