On 07/11/2018 05:48 AM, Michal Hocko wrote: > On Wed 11-07-18 14:47:11, Michal Hocko wrote: >> On Tue 10-07-18 11:49:03, Cannon Matthews wrote: >>> 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. >> >> The patch makes perfect sense to me. I wasn't even aware that it >> zeroying memblock allocation. Thanks for spotting this and fixing it. >> >>> Signed-off-by: Cannon Matthews <cannonmatthews@xxxxxxxxxx> >> >> I just do not think we need to to zero huge_bootmem_page portion of it. >> It should be sufficient to INIT_LIST_HEAD before list_add. We do >> initialize the rest explicitly already. > > Forgot to mention that after that is addressed you can add > Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cannon, How about if you make this change suggested by Michal, and I will submit a separate patch to revert the patch which added the phys field to huge_bootmem_page structure. FWIW, Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> -- Mike Kravetz
