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From: Andrew Morton <akpm@linux-foundation.org>
To: "Li Zhe" <lizhe.67@bytedance.com>
Cc: <apopple@nvidia.com>, <arnd@arndb.de>, <balbirs@nvidia.com>,
	<bp@alien8.de>, <dave.hansen@linux.intel.com>, <david@kernel.org>,
	<kees@kernel.org>, <mingo@redhat.com>, <muchun.song@linux.dev>,
	<rppt@kernel.org>, <tglx@kernel.org>,
	<linux-arch@vger.kernel.org>, <linux-hardening@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
	<x86@kernel.org>
Subject: Re: [PATCH v11 0/7] mm: optimize zone-device memmap initialization
Date: Mon, 31 Aug 2026 16:45:31 -0700	[thread overview]
Message-ID: <20260831164531.be5a8fa210401830e85eb974@linux-foundation.org> (raw)
In-Reply-To: <20260831111638.76012-1-lizhe.67@bytedance.com>

On Mon, 31 Aug 2026 19:16:31 +0800 "Li Zhe" <lizhe.67@bytedance.com> wrote:

> memmap_init_zone_device() can take a noticeable amount of time when large
> pmem namespaces are bound or rebound, because it initializes nearly
> identical struct page descriptors one PFN at a time. This series reduces
> that ZONE_DEVICE memmap initialization overhead by reusing prepared
> struct page templates and, on x86, using memcpy_nontemporal() for the
> template copy path.
> 
> ...
>
> This reduces the average memmap initialization time measured during
> rebind by about 48.0% for nd_pmem and 41.6% for dax_pmem on that arm64
> VM setup. Since this arm64 setup does not use the x86 MOVNTI fast paths,
> the result also suggests that the generic template-copy optimization can
> benefit architectures without an architecture-specific
> memcpy_nontemporal() backend.

Well that's nice.

Sashiko seems to have found some new things to complain about:
	https://sashiko.dev/#/patchset/20260831111638.76012-1-lizhe.67@bytedance.com



  parent reply	other threads:[~2026-08-31 23:45 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-31 11:16 [PATCH v11 0/7] mm: optimize zone-device memmap initialization Li Zhe
2026-08-31 11:16 ` [PATCH v11 1/7] mm: fix stale ZONE_DEVICE refcount comment Li Zhe
2026-08-31 11:16 ` [PATCH v11 2/7] mm: add a set_page_section_from_pfn() helper Li Zhe
2026-08-31 11:16 ` [PATCH v11 3/7] mm: add a template-based fast path for zone-device page init Li Zhe
2026-09-02  4:16   ` Mike Rapoport
2026-09-03  2:58     ` Li Zhe
2026-08-31 11:16 ` [PATCH v11 4/7] mm: extend the template fast path to zone-device compound tails Li Zhe
2026-09-02  4:18   ` Mike Rapoport
2026-08-31 11:16 ` [PATCH v11 5/7] string: introduce memcpy_nontemporal() Li Zhe
2026-08-31 11:16 ` [PATCH v11 6/7] mm: use memcpy_nontemporal() in zone-device template copies Li Zhe
2026-08-31 11:16 ` [PATCH v11 7/7] x86/string: extend memcpy_flushcache() fixed-size fastpaths Li Zhe
2026-08-31 23:45 ` Andrew Morton [this message]
2026-09-01  2:58   ` [PATCH v11 0/7] mm: optimize zone-device memmap initialization Li Zhe
2026-09-01 23:07     ` Andrew Morton

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