Re: [PATCH 0/4] mm/mm_init: simplify deferred init of struct pages

From: Wei Yang
Date: Tue Aug 19 2025 - 03:39:54 EST


On Mon, Aug 18, 2025 at 09:46:11AM +0300, Mike Rapoport wrote:
>From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>
>
>Hi,
>
>These patches simplify deferred initialization of the memory map.
>
>Beside nice negative diffstat I measured 3ms reduction in the
>initialization of deferred pages on single node system with 64GiB of RAM.

Nice cleanup.

For this series:

Reviewed-by: Wei Yang <richard.weiyang@xxxxxxxxx>

I guess the speed up is from "use a job per zone". So we do initialization per
zone instead of per memblock range in the zone, right?

>
>I don't have access to large memory machines, so I'd really appreciate
>testing of these patches on them to make sure there's no regression there.
>
>The patches are also available at git:
>https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git/log/?h=deferred-memmap-init/v1
>
>Mike Rapoport (Microsoft) (4):
> mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()
> mm/mm_init: deferred_init_memmap: use a job per zone
> mm/mm_init: drop deferred_init_maxorder()
> memblock: drop for_each_free_mem_pfn_range_in_zone_from()
>
> .clang-format | 1 -
> include/linux/memblock.h | 22 -----
> mm/memblock.c | 64 -------------
> mm/mm_init.c | 195 +++++++++++++--------------------------
> 4 files changed, 62 insertions(+), 220 deletions(-)
>
>
>base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
>--
>2.50.1
>

--
Wei Yang
Help you, Help me