Re: [PATCH v9 0/8] mm: optimize zone-device memmap initialization

From: Andrew Morton

Date: Mon Aug 03 2026 - 17:40:19 EST


On Mon, 3 Aug 2026 15:09:21 +0800 "Li Zhe" <lizhe.67@xxxxxxxxxxxxx> wrote:

> Test procedure:
> Rebind the nd_pmem and dax_pmem drivers 30 times and collect the memmap
> initialization time from the pr_debug() output of
> memmap_init_zone_device().
>
> Base(v7.2-rc1):
> Average of nd_pmem rebinds: 244.28 ms
> Average of dax_pmem rebinds: 273.31 ms
>
> With this series applied:
> Average of nd_pmem rebinds: 96.79 ms
> Average of dax_pmem rebinds: 119.04 ms
>
> This reduces the average memmap initialization time measured during
> rebind by about 60.4% for nd_pmem and 56.4% for dax_pmem.

Well that's nice.

Review is partial and it's late in the cycle so I'd prefer to schedule
this for the next -rc cycle.

AI review might have found a couple of things, please check?
https://sashiko.dev/#/patchset/20260803070929.86075-1-lizhe.67@xxxxxxxxxxxxx