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b=b//Lp6Y1qQq95x1/uaW18cJVPYVPCDOQz6cYK2G/bx2upGzZMLgieNpFC/FT8eYU4 9hZQSTwr29TmoktdLWXBZLcyop14PsjPoCIlFZzcJiiNpe7G+dTUGkLnD3363238nN E03456OTNBVdZArHUpbgc7eLCS4uSS7cQo9Oikw8= Date: Mon, 20 Jul 2026 15:43:34 -0700 From: Andrew Morton To: "Li Zhe" Cc: , , , , , , , , , , , , , , , Subject: Re: [PATCH v7 0/9] mm: optimize zone-device memmap initialization Message-Id: <20260720154334.b619e7b436d2dc2481b233ea@linux-foundation.org> In-Reply-To: <20260720120259.1545-1-lizhe.67@bytedance.com> References: <20260720120259.1545-1-lizhe.67@bytedance.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: C195FC0003 X-Stat-Signature: mcdebcn7eo5czuk788dypbxgoi91xrfk X-HE-Tag: 1784587416-716376 X-HE-Meta: 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 TiyaHYa3 7Mc5OpOMwK+wKg45IWey+B9ERAc5Oo1JPZqniYtvOKyB0niHGbiELiZVjY/jcG/1nMc5417yTWVurfpMqH7MYm3SsOZt8BRU9naVhjbDC9Ndo6RNNjM5WE7dHGNWDwhKW/KjLan+sSucNXtBpbvp/wrlLkiolOmetharOLVSzZJoKCGHOsDJCx42+Kh7xK6LslFRxEUI1v6suU6ayIUE1JE+hww34pYqY2/II+0Fgzqsh0t0X3KvcsFP7+BXzrKxawu6e6lNEoW0E8IJ8FQXXjOjHniALCz3iPAqL2yXUmyHNmMaykUDEHMnCg8poVwbPLmEQ+ZR/IOYsejdYbFheBiVKpQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, 20 Jul 2026 20:02:49 +0800 "Li Zhe" 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. What Dave said - more details on the real-world userspace benefit would be helpful, thanks. AI review might have found some things, one "critical": https://sashiko.dev/#/patchset/20260720120259.1545-1-lizhe.67@bytedance.com