When using 1GiB pages during early boot, use the new
memblock_virt_alloc_try_nid_raw() function 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.
To be safe, still zero the first sizeof(struct boomem_huge_page) bytes
since this is used a temporary storage place for this info until
gather_bootmem_prealloc() processes them later.
The rest of 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.
Signed-off-by: Cannon Matthews <cannonmatthews@xxxxxxxxxx>
---
mm/hugetlb.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3612fbb32e9d..c93a2c77e881 100644
--- 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) {
@@ -2109,7 +2109,12 @@ int __alloc_bootmem_huge_page(struct hstate *h)
* Use the beginning of the huge page to store the
* huge_bootmem_page struct (until gather_bootmem
* puts them into the mem_map).
+ *
+ * memblock_virt_alloc_try_nid_raw returns non-zero'd
+ * memory so zero out just enough for this struct, the
+ * rest will be zero'd on page fault.
*/
+ memset(addr, 0, sizeof(struct huge_bootmem_page));
m = addr;
goto found;
}
--
2.18.0.203.gfac676dfb9-goog
