From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 05BFC2D6E4B; Thu, 18 Dec 2025 08:44:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766047458; cv=none; b=cpWJNkuATTAG3D1hgbhHFHFFYyFy8RJ7knsqnORdrZUGKgJ/zDdKINwvg3I26T1XGaXz6PUvtQn17tFVZJmMo19huySnWOzF/yOPPf6eC4CWIXq5NnZ/7DcXTlYvme4B2OT1WXCY7U6mz6kUJsViBvt7Lks/7r+6fEfyUE2YEAQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766047458; c=relaxed/simple; bh=bALsCqvSTHwwYz8QmGh55URvGVsNoAOBLrpOS8lJtd4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=SDJ/QU5+GnNzuB/qCZ5hpnMdiYFi+8Sj4uF4rW/ZS7JGFMHvlHT7vIUrYZbuCBdg3LQNUCBgevBaGNrwHh6yGVSziYU5QN13jJkXGE4ryM6ngZs+6h/Fex+pbm15Vvw2zQEej+N8+91UF/NFWJ/mTpDEC2VzJLwR9HUewpZ4zOI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ukyez4lu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ukyez4lu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F222C4CEFB; Thu, 18 Dec 2025 08:44:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766047457; bh=bALsCqvSTHwwYz8QmGh55URvGVsNoAOBLrpOS8lJtd4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ukyez4lu8CFjM7JHpAeVJUdVpCmSNa2wj7Xmg4xLozKRmW+/KY0M+f0iioxKKlRTL MOUts3mwjSzKX67ovaxIYmBNpvgrrAzZ9u6ATvCzXCBkLXJbIsMCNErjsHjF8TxrXa wKWVwOruiNMyYjvM1EA+WfC7ufzB4g/NF7tjwsmrZnbvvJVNIkamoprSGdtnrT0cdu A29w2x9UtFTaS+jALpDaZr/zllPmWQHu6NgzdCLlKIQhzuw7A5NZovaTCoCqUtTg1d XERd6gK0dUi9ML0LgD4E+lq+5eyToLHmBKOEgsF3eKAVuabLCKU8mXzruRiNi6sZiS yEX5hzI3wzYwg== Message-ID: Date: Thu, 18 Dec 2025 09:44:11 +0100 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] sparc: Use vmemmap_populate_hugepages for vmemmap_populate To: chengkaitao , davem@davemloft.net, andreas@gaisler.com, akpm@linux-foundation.org, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com Cc: kevin.brodsky@arm.com, dave.hansen@linux.intel.com, ziy@nvidia.com, chengkaitao@kylinos.cn, willy@infradead.org, zhengqi.arch@bytedance.com, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20251217120858.18713-1-pilgrimtao@gmail.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: <20251217120858.18713-1-pilgrimtao@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/17/25 13:08, chengkaitao wrote: > From: Chengkaitao > > 1. Added the vmemmap_false_pmd function to accommodate architectures > that do not support basepages. > 2. In the SPARC architecture, reimplemented vmemmap_populate using > vmemmap_populate_hugepages. > > Signed-off-by: Chengkaitao > --- > arch/sparc/mm/init_64.c | 56 ++++++++++++++++------------------------- > include/linux/mm.h | 1 + > mm/sparse-vmemmap.c | 7 +++++- > 3 files changed, 28 insertions(+), 36 deletions(-) > > diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c > index df9f7c444c39..a80cdfa6ba98 100644 > --- a/arch/sparc/mm/init_64.c > +++ b/arch/sparc/mm/init_64.c > @@ -5,7 +5,7 @@ > * Copyright (C) 1996-1999 David S. Miller (davem@caip.rutgers.edu) > * Copyright (C) 1997-1999 Jakub Jelinek (jj@sunsite.mff.cuni.cz) > */ > - > + > #include > #include > #include > @@ -2397,11 +2397,11 @@ void __init paging_init(void) > * work. > */ > init_mm.pgd += ((shift) / (sizeof(pgd_t))); > - > + > memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir)); > > inherit_prom_mappings(); > - > + > /* Ok, we can use our TLB miss and window trap handlers safely. */ > setup_tba(); > Bunch of unrelated changes that should not go in here. > @@ -2581,8 +2581,8 @@ unsigned long _PAGE_CACHE __read_mostly; > EXPORT_SYMBOL(_PAGE_CACHE); > > #ifdef CONFIG_SPARSEMEM_VMEMMAP > -int __meminit vmemmap_populate(unsigned long vstart, unsigned long vend, > - int node, struct vmem_altmap *altmap) > +void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node, > + unsigned long addr, unsigned long next) > { > unsigned long pte_base; > > @@ -2595,39 +2595,25 @@ int __meminit vmemmap_populate(unsigned long vstart, unsigned long vend, > > pte_base |= _PAGE_PMD_HUGE; > > - vstart = vstart & PMD_MASK; > - vend = ALIGN(vend, PMD_SIZE); > - for (; vstart < vend; vstart += PMD_SIZE) { > - pgd_t *pgd = vmemmap_pgd_populate(vstart, node); > - unsigned long pte; > - p4d_t *p4d; > - pud_t *pud; > - pmd_t *pmd; > - > - if (!pgd) > - return -ENOMEM; > - > - p4d = vmemmap_p4d_populate(pgd, vstart, node); > - if (!p4d) > - return -ENOMEM; > - > - pud = vmemmap_pud_populate(p4d, vstart, node); > - if (!pud) > - return -ENOMEM; > - > - pmd = pmd_offset(pud, vstart); > - pte = pmd_val(*pmd); > - if (!(pte & _PAGE_VALID)) { > - void *block = vmemmap_alloc_block(PMD_SIZE, node); > + pmd_val(*pmd) = pte_base | __pa(p); > +} > > - if (!block) > - return -ENOMEM; > +bool __meminit vmemmap_false_pmd(pmd_t *pmd, int node) > +{ > + return true; > +} > > - pmd_val(*pmd) = pte_base | __pa(block); > - } > - } > +int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node, > + unsigned long addr, unsigned long next) > +{ > + vmemmap_verify((pte_t *)pmdp, node, addr, next); > + return 1; > +} > > - return 0; > +int __meminit vmemmap_populate(unsigned long vstart, unsigned long vend, > + int node, struct vmem_altmap *altmap) > +{ > + return vmemmap_populate_hugepages(vstart, vend, node, altmap); > } > #endif /* CONFIG_SPARSEMEM_VMEMMAP */ > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 15076261d0c2..5e005b0f947d 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -4248,6 +4248,7 @@ void *vmemmap_alloc_block_buf(unsigned long size, int node, > void vmemmap_verify(pte_t *, int, unsigned long, unsigned long); > void vmemmap_set_pmd(pmd_t *pmd, void *p, int node, > unsigned long addr, unsigned long next); > +bool vmemmap_false_pmd(pmd_t *pmd, int node); > int vmemmap_check_pmd(pmd_t *pmd, int node, > unsigned long addr, unsigned long next); > int vmemmap_populate_basepages(unsigned long start, unsigned long end, > diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c > index 37522d6cb398..bd54b8c6f56e 100644 > --- a/mm/sparse-vmemmap.c > +++ b/mm/sparse-vmemmap.c > @@ -407,6 +407,11 @@ void __weak __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node, > { > } > > +bool __weak __meminit vmemmap_false_pmd(pmd_t *pmd, int node) > +{ > + return 0; > +} > + Reading that function I have absolutely no clue what this is supposed to do. :) Also, why are you passing pmd+node when sparc ignores them completely and statically returns "true" ? If you can tell me what the semantics of that function should be, maybe we can come up with a more descriptive name. -- Cheers David