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 8B38442EEBA; Mon, 29 Jun 2026 15:04:24 +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=1782745465; cv=none; b=rMr4QCR+MLHP3IYdXb9IVyec0+K9NzD3SEnf62qQQCqA5DB3qIHW6mPQx59DBZcACJ/9//jQQMDNoYj+IbSyjeWqbCwryViWfzhE8tMvZIlXXnAUPsyg7l0wcDSCWjljuM5jSc2bZWii7FKypTcCeWQeb9qq/DAQgTMBNwvt/28= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782745465; c=relaxed/simple; bh=SYaVXt+IV8k9IprMmFlL40jrqkI+bjDFhw+L/e/x6c0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HDUcbKhXU9iewW1hIYqKvy4Hti8xJJmYQGZOuEMBWmoaQYT48TEx+UglRxtNrudL+Qoevsz3I2A+DQk9Et/aFuovYPQbA29NPokwF0s70babqqzqFau6bZJ6/Jy7yWXZwScc2ET0XKlTUqP2GHHVfKTqWfWH0CQ22UZXbpg0TKo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QFio7RIW; 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="QFio7RIW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7841C1F000E9; Mon, 29 Jun 2026 15:04:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782745464; bh=njjcJ09hvKJm4DFqkApGQjO9fSrNvBtEtkEmL7ywa5s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QFio7RIWh9qUVn1KVNLiBit78SH4LLPizL9FqW44jft3Vr2XWCwkPsbHTRqAbVO4i DJXgerUwodYxfWKcGXfcssCek5si/ANwdkXnMZhQgEMPxruwf5PA6K88Y+YLkWYmPN pqun5hdQ0I/Y2M9MfQ0ZvZe9JaGaCs26z9fzx3WJ4pk3cJhdxcqGKMPujyWgU3gMQ7 sgnf68WV4U9Hr9uUvEskGcjMWVcyQ/J+lolia5Ft96QzWnOSu1bbBaokxkY7TsUtjJ PqkHMy1ywX/SP9fteMIBK0hpuqMI8GsM2dHkxcyofmZO9SiMt9YQnJl0R1Rsj0OhmM NA6OfaQrULYbA== From: Lorenzo Stoakes To: Andrew Morton Cc: David Hildenbrand , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Matthew Wilcox , Jan Kara , Rik van Riel , Harry Yoo , Jann Horn , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Xu Xin , Chengming Zhou , Miaohe Lin , Naoya Horiguchi , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Pedro Falcato , Peter Xu , Kees Cook , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [RFC PATCH 08/10] mm: introduce and use linear_folio_page_index() Date: Mon, 29 Jun 2026 16:03:48 +0100 Message-ID: <58b4246bd0cd8b58f86ae7ce2acd54f9f478445a.1782745153.git.ljs@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This function is, for now, a placeholder; it will be used in future to determine whether to use the virtual page index or not, based on whether the folio is anonymous or not. Currently it simply wraps linear_page_index(), so this does not change behaviour. We update callers that will, once the change is introduced to track anonymous folios by virtual page offset if MAP_PRIVATE file-backed, need to determine which index to use based on folio type. No functional change intended. Signed-off-by: Lorenzo Stoakes --- include/linux/pagemap.h | 18 ++++++++++++++++++ mm/huge_memory.c | 3 ++- mm/migrate.c | 6 ++++-- mm/userfaultfd.c | 6 ++++-- 4 files changed, 28 insertions(+), 5 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 6e0d719d639a..e2affa57dadd 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -1146,6 +1146,24 @@ static inline pgoff_t linear_virt_page_index(const struct vm_area_struct *vma, return pgoff; } +/** + * linear_folio_page_index() - Determine the absolute page offset of + * @address within @vma from @folio. + * @folio: The folio whose linear page index is sought. + * @vma: The VMA in which @address resides. + * @address: The address whose absolute page offset is required. + * + * For compatibility, currently identical to linear_page_index(). + * + * Returns: The absolute page offset of @address within @vma. + */ +static inline pgoff_t linear_folio_page_index(const struct folio *folio, + const struct vm_area_struct *vma, + const unsigned long address) +{ + return linear_page_index(vma, address); +} + struct wait_page_key { struct folio *folio; int bit_nr; diff --git a/mm/huge_memory.c b/mm/huge_memory.c index e94f56487225..1b3456a9ff74 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2832,7 +2832,8 @@ int move_pages_huge_pmd(struct mm_struct *mm, pmd_t *dst_pmd, pmd_t *src_pmd, pm } folio_move_anon_rmap(src_folio, dst_vma); - src_folio->index = linear_page_index(dst_vma, dst_addr); + src_folio->index = linear_folio_page_index(src_folio, dst_vma, + dst_addr); _dst_pmd = folio_mk_pmd(src_folio, dst_vma->vm_page_prot); /* Follow mremap() behavior and treat the entry dirty after the move */ diff --git a/mm/migrate.c b/mm/migrate.c index d9b23909d716..4250a56e09c0 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -358,8 +358,10 @@ static bool remove_migration_pte(struct folio *folio, unsigned long idx = 0; /* pgoff is invalid for ksm pages, but they are never large */ - if (folio_test_large(folio) && !folio_test_hugetlb(folio)) - idx = linear_page_index(vma, pvmw.address) - pvmw.pgoff; + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) { + idx += linear_folio_page_index(folio, vma, pvmw.address); + idx -= pvmw.pgoff; + } new = folio_page(folio, idx); #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index bf4518f4449d..9c6b1a678ca6 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -1283,7 +1283,8 @@ static long move_present_ptes(struct mm_struct *mm, } folio_move_anon_rmap(src_folio, dst_vma); - src_folio->index = linear_page_index(dst_vma, dst_addr); + src_folio->index = linear_folio_page_index(src_folio, dst_vma, + dst_addr); orig_dst_pte = folio_mk_pte(src_folio, dst_vma->vm_page_prot); /* Set soft dirty bit so userspace can notice the pte was moved */ @@ -1352,7 +1353,8 @@ static int move_swap_pte(struct mm_struct *mm, struct vm_area_struct *dst_vma, */ if (src_folio) { folio_move_anon_rmap(src_folio, dst_vma); - src_folio->index = linear_page_index(dst_vma, dst_addr); + src_folio->index = linear_folio_page_index(src_folio, dst_vma, + dst_addr); } else { /* * Check if the swap entry is cached after acquiring the src_pte -- 2.54.0