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 30EEF43A7E5 for ; Wed, 15 Jul 2026 09:47:22 +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=1784108845; cv=none; b=OMyXczHK+K0l16OSBS8U4w8X4eGI5CDnPuzCh8KMqfSq5Vl1DKYSvHOWyPj1VwmmXql/3goBhx50/Ov9o+mNX/6RMJpOOnb0bNQ2B4Z2lqaQI6T+pRppopGmgC/qOg3TtQe6lz0DhAymkim2AoGzl06/U7EeBG83yr5MxJb46uI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784108845; c=relaxed/simple; bh=OW21ceh5OmRze1zxR4HHfBcaZM12bxTfVgY6CCPiZas=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SbproqIv/0/BHK0DZO/3Z7vufoWlBvnM7OdBbls+IDuyU1UyCnh1JlKfwahppVuX/ynm1u5ojBXK2hBjjYxRZRtEjCiWHU1eLrFPaSnBVODaXavZjMDhY06dd0Y6wu+Mn45V+PAFIJ8G8snKskoqipUHaLUV0BVTMg0tuXgFiok= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GbYIVoeB; 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="GbYIVoeB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13C0A1F000E9; Wed, 15 Jul 2026 09:47:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784108840; bh=K+nXF5kGt/5WK2ttK+PIxcJ4KC4Tyq4BW2OUT5V+T5c=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=GbYIVoeB6t+if8qITH2oBmRvxiE0XyNjEoSDoDz9ra1khtLK8AVjlZqTRtXiHo2nb wZzwHcc7FAhtCbY7ySSxmSSDyTfLS4CJkmPVaPhokzKCShfdtV6Lr67EKh1/OdNZMU FdkzP6ZGLegK7h4tYTfhtQfxTJThydMFoWLlP+v7G18AxAZC0kwvknTeNBNtwrOGt/ VxD4iTLolh69xeDSXT2y6dAXlCLWqJYbjWf19QlWJLqdYQKn3rtDGqeSNx8ApJV23I q4d7y3xoQJfYW1+QvG+ceTZBNB54k71KdEuf7Suy/bjvj+XPlpdAcAS3ikWDPo6leZ 1Ruz8bn51V4MQ== Date: Wed, 15 Jul 2026 12:47:13 +0300 From: Mike Rapoport To: Muchun Song Cc: Muchun Song , Andrew Morton , Oscar Salvador , David Hildenbrand , linux-mm@kvack.org, Vlastimil Babka , Lorenzo Stoakes , Michal Hocko , linux-kernel@vger.kernel.org Subject: Re: [PATCH 04/17] mm/mm_init: skip initializing shared vmemmap tail pages Message-ID: References: <20260702093821.2740183-1-songmuchun@bytedance.com> <20260702093821.2740183-5-songmuchun@bytedance.com> <178409212283.638342.13179685803375053525.b4-review@b4> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jul 15, 2026 at 05:11:21PM +0800, Muchun Song wrote: > > On Jul 15, 2026, at 13:08, Mike Rapoport wrote: > > > >> --- a/mm/internal.h > >> +++ b/mm/internal.h > >> @@ -1002,10 +1002,26 @@ static inline void sparse_init(void) {} > >> */ > >> #ifdef CONFIG_SPARSEMEM_VMEMMAP > >> void sparse_init_subsection_map(void); > >> + > >> +static inline bool page_vmemmap_optimizable(const struct page *page, unsigned int order) > >> +{ > >> + const unsigned long pfn = page_to_pfn(page); > >> + const unsigned long nr_pages = 1UL << order; > >> + > > > > Don't you want to gate it on HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON? > > You mean HUGETLB_PAGE_OPTIMIZE_VMEMMAP, right? HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON > could be off when user enable HVO via cmdline. Yes -- Sincerely yours, Mike.