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 7D8D724DCF6 for ; Mon, 13 Apr 2026 16:08:32 +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=1776096512; cv=none; b=VRbyN2OdsYIkBy66HaOrcWKlNc4qVneEWgpxLB+hCQacdWN3M/NTDJLMWSzLB8kbBEl+X8aqu3buehS8kmq8WHPI0OoXndcse+qhikGuLgNu+yfCIdpv9YlVxiGGT5M7fUIlaxJ4v7ggUGtADOL+ObM+k//xXCB638KikSEgnwg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776096512; c=relaxed/simple; bh=d825AxCCibvEeW1TS9m6BI8YXTIqv9i5TOVSoBg9bsE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=M26eLIdt62pdl8OyIH3+eOJ+6gexNfRidurQXYcmZJmOJC3IpFvoZ1eEOaGDCJC5sl8wO6TV8TcEY+Y1tP5h7nXPlbIUHWmlKOtHrVBE5Lqs3x0kKvwZ6w1U+EtPlTVdkvHegaGA/jWqUIQ5ZCyCt1NUtJ41PxNrR5+RUTGH3HA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sLgD6aLf; 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="sLgD6aLf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EDA7DC2BCAF; Mon, 13 Apr 2026 16:08:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776096512; bh=d825AxCCibvEeW1TS9m6BI8YXTIqv9i5TOVSoBg9bsE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sLgD6aLfOKT7I8UT9/pGuAtkMNU5pKGEL+PmzpXyknCX2JRD/MRLmW2OFA1NXCBV/ pdNzou3dwWx0Uip+kPcPhz6Ssaf065a5j+vm67Z9UbAeN3SMeG3pcalhKpRgi5xE4h 1/LYDpv7k8YMyKW+DJSNTmXqViWmyKOxRAw0fif2wbom7DHAAXR91i795M8Rg6OZfo /y8nJZdclPaiVSHaBYwKR4PnasxsqZSOP1HAXlsxAmobUCVQjz7yEmlBOzItOprJed lxWDMuCTHJcoMzIAvs8Mb1YriQKypH1b9btDAkpEUwwe+0zwS4eImaEcqa2TmbCJlT ubo+kfd4RY8Cg== Date: Mon, 13 Apr 2026 19:08:24 +0300 From: Mike Rapoport To: "Barry Song (Xiaomi)" Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, urezki@gmail.com, linux-kernel@vger.kernel.org, anshuman.khandual@arm.com, ryan.roberts@arm.com, ajd@linux.ibm.com, david@kernel.org, Xueyuan.chen21@gmail.com Subject: Re: [RFC PATCH 3/8] mm/vmalloc: Extend vmap_small_pages_range_noflush() to support larger page_shift sizes Message-ID: References: <20260408025115.27368-1-baohua@kernel.org> <20260408025115.27368-4-baohua@kernel.org> 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: <20260408025115.27368-4-baohua@kernel.org> Hi Barry, On Wed, Apr 08, 2026 at 10:51:10AM +0800, Barry Song (Xiaomi) wrote: > vmap_small_pages_range_noflush() provides a clean interface by taking > struct page **pages and mapping them via direct PTE iteration. This > avoids the page table zigzag seen when using > vmap_range_noflush() for page_shift values other than PAGE_SHIFT. > > Extend it to support larger page_shift values, and add PMD- and > contiguous-PTE mappings as well. > > Signed-off-by: Barry Song (Xiaomi) > --- > mm/vmalloc.c | 54 ++++++++++++++++++++++++++++++++++++++++------------ > 1 file changed, 42 insertions(+), 12 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 57eae99d9909..5bf072297536 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -524,8 +524,9 @@ void vunmap_range(unsigned long addr, unsigned long end) > > static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, > unsigned long end, pgprot_t prot, struct page **pages, int *nr, > - pgtbl_mod_mask *mask) > + pgtbl_mod_mask *mask, unsigned int shift) > { > + unsigned int steps = 1; > int err = 0; > pte_t *pte; > > @@ -543,6 +544,7 @@ static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, > do { > struct page *page = pages[*nr]; > > + steps = 1; > if (WARN_ON(!pte_none(ptep_get(pte)))) { > err = -EBUSY; > break; > @@ -556,9 +558,24 @@ static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, > break; > } > > +#ifdef CONFIG_HUGETLB_PAGE Why is this related to HUGETLB_PAGE? > + if (shift != PAGE_SHIFT) { > + unsigned long pfn = page_to_pfn(page), size; > + > + size = arch_vmap_pte_range_map_size(addr, end, pfn, shift); > + if (size != PAGE_SIZE) { > + steps = size >> PAGE_SHIFT; > + pte_t entry = pfn_pte(pfn, prot); > + > + entry = arch_make_huge_pte(entry, ilog2(size), 0); > + set_huge_pte_at(&init_mm, addr, pte, entry, size); > + continue; > + } > + } > +#endif > + > set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); > - (*nr)++; > - } while (pte++, addr += PAGE_SIZE, addr != end); > + } while (pte += steps, *nr += steps, addr += PAGE_SIZE * steps, addr != end); > > lazy_mmu_mode_disable(); > *mask |= PGTBL_PTE_MODIFIED; > @@ -568,7 +585,7 @@ static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, > > static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr, > unsigned long end, pgprot_t prot, struct page **pages, int *nr, > - pgtbl_mod_mask *mask) > + pgtbl_mod_mask *mask, unsigned int shift) > { > pmd_t *pmd; > unsigned long next; > @@ -578,7 +595,20 @@ static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr, > return -ENOMEM; > do { > next = pmd_addr_end(addr, end); > - if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask)) > + > + if (shift == PMD_SHIFT) { > + struct page *page = pages[*nr]; > + phys_addr_t phys_addr = page_to_phys(page); > + > + if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot, > + shift)) { > + *mask |= PGTBL_PMD_MODIFIED; > + *nr += 1 << (shift - PAGE_SHIFT); > + continue; > + } With this vmap_pages_pmd_range() looks quite similar to vmap_pmd_range(). Any changes we can consolidate the two? > + } > + > + if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask, shift)) > return -ENOMEM; > } while (pmd++, addr = next, addr != end); > return 0; -- Sincerely yours, Mike.