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> -- Michal Hocko SUSE Labs
