Linux kernel: the role of zero page allocation during paging_init

Question

I am trying to understand the kernel memory reserve at boot for arch / arm.

Paging_init () is called here to set the page tables, initialize the zone’s memory card, etc. c setup_arch(). He also highlights one zero pagebefore the distribution of the actual mem_map.

void __init paging_init(const struct machine_desc *mdesc)
{
    void *zero_page;
    ---
    zero_page = early_alloc(PAGE_SIZE);
    ---
    empty_zero_page = virt_to_page(zero_page);
    __flush_dcache_page(NULL, empty_zero_page);
}

Can someone explain the role zero page?

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Answer 1

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