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

Andrew Morton <[email protected]> Mon, 3 Aug 2026 14:40:14 -0700

Newsgroups	org.kernel.vger.linux-arch,org.kernel.vger.linux-hardening,org.kernel.vger.linux-kernel,org.kvack.linux-mm
Message-ID	<[email protected]>

On Mon,  3 Aug 2026 15:09:21 +0800 "Li Zhe" <[email protected]> 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/[email protected]