From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 17C233845A7; Tue, 29 Sep 2026 07:16:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790666204; cv=none; b=oj0L/W9yYa4jxsmCwYmXwGo8yMxzhg4d+t6ZyZHHTJFo9Q+YlysuHzDk7Vh7BXhmatQOrL+z5KvZ0HvYPWjcPcMWIcXMmHSbK5xLAFAFFkdWqovHpReOJ5xPEZSoj4gSDovW1FYIqf9YwjTBF8wbMWH1yX6mdBE9/RwmtCvpGXM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790666204; c=relaxed/simple; bh=AiJujK6ouuxLt7zZTtXQs6Rq3ANHVpanJKJyIyICCdU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nyKFfUQhxiDtsHZc6H8rRN+jzvRWEjFptIs9+Iyk6COMKhsYOmGkxRNze7jQfoAYtvP125mInzSn7AxFFd60Ke52dn/uiQQO+qIwpGh1+xBanC07Ggdn1Tizg2ZNJWvhmF160632vfDr2iD2HwvEGbPmIVSPrCZF8e/6pIQp6qE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XPvIhzZV; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XPvIhzZV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95BBB1F00898; Tue, 29 Sep 2026 07:16:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790666202; bh=lAgsxeuo1uwHONfqh8pxHditw8tVE9dP/mYZuc/xVh8=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=XPvIhzZVscw0/cIG0nNlyQJokQTnSAf2sVHgbX/GtyrbGyCa9VYZCF03+80v4yyBe T6BnIW4SEgx/0905eYA6L0YqyQfMPD4ZxPieJLrEijDAEAK1QXGh2PQodJ2iPg7ip+ bsF4tNu9o+DEnz08puq3XIu8kQWM8gWwa7fBeI3tUGiSs7JNuq0lfJ+Rkk2sqFpf2e 2i0w1njrIONG0cBXMFQbOWvlDJiCkgblfTEAQyKEIBYTNyIqkx2fZGFwsaSuNM73Rk 22v9ZCodwNJwGKjsqEBxrY8hP38UnJAbvN/N1sdidyje7sTphU6cS6JCCQWoO4USUA LqQKah1HtBqBw== Message-ID: <5c73e3b9-4eca-4b84-ba3d-85bb7d6f77dc@kernel.org> Date: Tue, 29 Sep 2026 09:16:37 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 01/12] mm/sparse-vmemmap: factor out shared vmemmap tail page allocation To: Muchun Song , Andrew Morton , Oscar Salvador , Madhavan Srinivasan , Michael Ellerman , Jonathan Corbet Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org, Muchun Song , Lorenzo Stoakes , Mike Rapoport , Qi Zheng , Nicholas Piggin , Christophe Leroy , Randy Dunlap , Lance Yang References: <20260927025441.741633-1-songmuchun@bytedance.com> <20260927025441.741633-2-songmuchun@bytedance.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/27/26 04:54, Muchun Song wrote: > HugeTLB and sparse-vmemmap each have their own helper to allocate the > shared vmemmap tail page used by vmemmap optimization. > > Factor that logic into a common vmemmap_shared_tail_page() helper. It > allocates the page through vmemmap_alloc_block(), initializes the tail > struct pages, and uses cmpxchg() to install the per-zone shared page. > > This removes duplicate allocation logic while handling both early boot > and runtime allocation through the same helper. > > Signed-off-by: Muchun Song > Acked-by: Qi Zheng > Acked-by: Mike Rapoport (Microsoft) > --- > v5: > - Move this patch before CONFIG_VMEMMAP_OPTIMIZATION is introduced > > v4: > - Update the commit message for the renamed VMEMMAP_OPTIMIZATION config > - Collect Acked-by from Mike Rapoport > > v2: > - Collect Acked-by from Qi Zheng > --- [...] > > #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP > -static __meminit struct page *vmemmap_get_tail(unsigned int order, struct zone *zone) > +struct page __ref *vmemmap_shared_tail_page(unsigned int order, struct zone *zone) > { > - struct page *p, *tail; > - unsigned int idx; > - int node = zone_to_nid(zone); > + void *addr; > + struct page *page; > + const unsigned int idx = order - VMEMMAP_OPTIMIZATION_MIN_ORDER; Nit: constants read much nicer all the way at the top. Acked-by: David Hildenbrand (Arm) -- Cheers, David