mm/hugetlb.c: don't zero 1GiB bootmem pages

When using 1GiB pages during early boot, use the new
memblock_virt_alloc_try_nid_raw() to allocate memory without zeroing it.
Zeroing out hundreds or thousands of GiB in a single core memset() call
is very slow, and can make early boot last upwards of 20-30 minutes on
multi TiB machines.

The memory does not need to be zero'd as the hugetlb pages are always
zero'd on page fault.

Tested: Booted with ~3800 1G pages, and it booted successfully in
roughly the same amount of time as with 0, as opposed to the 25+ minutes
it would take before.

Link: http://lkml.kernel.org/r/20180711213313.92481-1-cannonmatthews@google.com
Signed-off-by: Cannon Matthews <cannonmatthews@google.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: David Matlack <dmatlack@google.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 4cea30a..47566bb 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2101,7 +2101,7 @@ int __alloc_bootmem_huge_page(struct hstate *h)
        for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
                void *addr;
 
-               addr = memblock_virt_alloc_try_nid_nopanic(
+               addr = memblock_virt_alloc_try_nid_raw(
                                huge_page_size(h), huge_page_size(h),
                                0, BOOTMEM_ALLOC_ACCESSIBLE, node);
                if (addr) {
@@ -2119,6 +2119,7 @@ int __alloc_bootmem_huge_page(struct hstate *h)
 found:
        BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h)));
        /* Put them into a private list first because mem_map is not up yet */
+       INIT_LIST_HEAD(&m->list);
        list_add(&m->list, &huge_boot_pages);
        m->hstate = h;
        return 1;