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 7087925C6E2 for ; Fri, 7 Nov 2025 08:48:44 +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=1762505324; cv=none; b=psPXXdpmxO1IeG8o3kqy6QDjJEVZ0jL4IE30FyhtsT4rCIyhAsFY8qq4ZQWvC4HD5xh81E5EX9hykzFV6J7nvCfgpzuzpHWb8KW4MS1VQyDTL1qTqePBAfnkIJ0Wi4tjkIu1gZZWHydirlSpqduPwssVn9JjHkhUEpilXMcsm1Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762505324; c=relaxed/simple; bh=E3TwJzPNvZUaml5cZpTDTUQufuUCSzPOAK8264B+Oms=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=JgJ6K9u7qfPcFz6v6pvQn/KuqWP6k+srJltP6DSl8k5WnveWHUAr8fcz5AWjV3vu6/Vsm5bPDd8OKMeUl/BK0TDUydm85fGpL9a6cs8V/0l/e6Mym74e8nFCBNA4h9xdkaEFLZ3H70RmRlJqHkX7U8tVa2th3zfdeSOvzXgadZw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Rf/i0p2W; 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="Rf/i0p2W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AE20C4CEF8; Fri, 7 Nov 2025 08:48:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762505324; bh=E3TwJzPNvZUaml5cZpTDTUQufuUCSzPOAK8264B+Oms=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Rf/i0p2WMdBHgz6Jt2saUAD8COs+9ceeeVFfjJ0Mj7t4/8ZMJc7cXG10Il75xumNO JAmz4UB+O0L1zs1qS8DH0pFitMi20s0t6y+q1DpCfuvjV2wgDnli+QLRgAZdWgSptx fwqaGMdEgPrPBXL4Y0fjavTXbcW3s3eU1UsbS8zcDTdz/TohFk3GVHD1QBYLfedUeh 96oVrENtNESgRixnXbHp2hwjA9bRgroHzEFz5TT1KdkGECjdnL/H09WyxZCZLc6jeX 3Wokhb6gem3x2YIIaH/O0H1E/vwfSvW7LQuenGG8lycjBlxAzxireur3rTqC6e6+oJ ARmVb98KojHDQ== Message-ID: Date: Fri, 7 Nov 2025 09:48:37 +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 v8 3/7] mm/highmem: introduce clear_user_highpages() To: Ankur Arora , linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Cc: akpm@linux-foundation.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, mjguzik@gmail.com, luto@kernel.org, peterz@infradead.org, acme@kernel.org, namhyung@kernel.org, tglx@linutronix.de, willy@infradead.org, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com References: <20251027202109.678022-1-ankur.a.arora@oracle.com> <20251027202109.678022-4-ankur.a.arora@oracle.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: <20251027202109.678022-4-ankur.a.arora@oracle.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 27.10.25 21:21, Ankur Arora wrote: > Define clear_user_highpages() which clears pages sequentially using > the single page variant. > > With !CONFIG_HIGHMEM, pages are contiguous so use the range clearing > primitive clear_user_pages(). > > Signed-off-by: Ankur Arora > > Note: fixed That should be dropped. > --- > include/linux/highmem.h | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/include/linux/highmem.h b/include/linux/highmem.h > index 105cc4c00cc3..c5f8b1556fd7 100644 > --- a/include/linux/highmem.h > +++ b/include/linux/highmem.h > @@ -199,6 +199,11 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size) > > /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ > #ifndef clear_user_highpage > +/** > + * clear_user_highpage() - clear a page to be mapped to user space > + * @page: start page > + * @vaddr: start address of the user mapping > + */ > static inline void clear_user_highpage(struct page *page, unsigned long vaddr) > { > void *addr = kmap_local_page(page); > @@ -207,6 +212,30 @@ static inline void clear_user_highpage(struct page *page, unsigned long vaddr) > } > #endif > > +/** > + * clear_user_highpages() - clear a page range to be mapped to user space > + * @page: start page > + * @vaddr: start address of the user mapping > + * @npages: number of pages > + * > + * Assumes that all the pages in the region (@page, +@npages) are valid > + * so this does no exception handling. > + */ > +static inline void clear_user_highpages(struct page *page, unsigned long vaddr, > + unsigned int npages) > +{ > + if (!IS_ENABLED(CONFIG_HIGHMEM)) { > + clear_user_pages(page_address(page), vaddr, page, npages); > + return; > + } > + > + do { > + clear_user_highpage(page, vaddr); > + vaddr += PAGE_SIZE; > + page++; > + } while (--npages); > +} > + > #ifndef vma_alloc_zeroed_movable_folio > /** > * vma_alloc_zeroed_movable_folio - Allocate a zeroed page for a VMA. Acked-by: David Hildenbrand (Red Hat) -- Cheers David