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 642F7476CDE; Wed, 29 Jul 2026 16:50:03 +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=1785343804; cv=none; b=gYkxRXYrnXk1MGesMmVC1RFuAjae1UXZgC0qJ9EhYbbvxZWk9HHvRvEqtwFeyNAMzcDat9fIZEcJnJ8rrK0RMRKjDrbRj/fZJEfbNrS3iVCVQORacPsNtbfLlXDUQ9/MkwquX7hYrnYldhDz+D133S6X+9nqMbbSPdtshU2Y4LI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785343804; c=relaxed/simple; bh=m5dOVubk6tLd79kxflPffqxGXd+ky2y8r1AEA3ss3P4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Y68GpkS1AQdj3x6bVhLUIBfYLS5Y/vXztSUnex65SbUlBAl2753Ft4LLHrnKgS5Xcgs55PiCBJrkyWZPR/f6IHfP4tKxRNGT+H5hBUjzAQKQg/DxE6SYN/wNVNv4vT0a6AS7kkkt14uvzjPQIe1PBPM0I1lTmJVNHQ3mK2IrDeM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NZsre0Pw; 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="NZsre0Pw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F1A6E1F000E9; Wed, 29 Jul 2026 16:49:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785343803; bh=3mOY2tRVEvGkY0yTiPgUewN8py54kSX5AHzNPcNUQhw=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=NZsre0PwgRZlHfbyFdxByTmlEwRhYdKx0qIduaLvKEDkN0uCoghZNZ/B5msbqL9a0 oYejioiTMikzBdcYjzPvFSBJKlm4l8sm6p0Ce1aydSGIJkoPiDHGjIvZQ5yS5BO2Dq 9Qh7O4cLvimf6W5Bk8Z9KAjdKCN6n6Ru22kX1Ak8uIqGmddO1okfSix5nk7yenRYiY f05taAA7627d2zrva0Ujn8f4tm9mDGw51Z0oydcWYc5M7Ycb4+BSMpI8sOZNps5SUA 6BJWAJqJR8/v3nwgzmhZyhfrQW5wQg97YtzMK5ubosrSGK5iPHtB9V4pPSJtX6AMxt +bgxjF+mC/ZLg== From: "Lorenzo Stoakes (ARM)" Date: Wed, 29 Jul 2026 17:48:42 +0100 Subject: [PATCH v3 07/15] mm/rmap: track whether the page VMA mapped pgoff is anonymous 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="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260729-b4-scalable-cow-virt-pgoff-v3-7-e8ecfefea812@kernel.org> References: <20260729-b4-scalable-cow-virt-pgoff-v3-0-e8ecfefea812@kernel.org> In-Reply-To: <20260729-b4-scalable-cow-virt-pgoff-v3-0-e8ecfefea812@kernel.org> To: Andrew Morton , David Hildenbrand , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , "Matthew Wilcox (Oracle)" , Jan Kara , Miaohe Lin , Naoya Horiguchi , Rik van Riel , Harry Yoo , Lance Yang , Kees Cook , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Usama Arif , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Peter Xu , Xu Xin , Chengming Zhou , Arnd Bergmann , Greg Kroah-Hartman Cc: "Lorenzo Stoakes (ARM)" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=3644; i=ljs@kernel.org; h=from:subject:message-id; bh=m5dOVubk6tLd79kxflPffqxGXd+ky2y8r1AEA3ss3P4=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLKy9H7c8rqiKZSoE6R97d+2x8f66xpuneLSTE3aPcU+h f2oQ82cjlIWBjEuBlkxRZbnX8T3B4mEzeu84O8GM4eVCWQIAxenAExEN4Lhf2jzX6nmjAWeN/lY +tnnv12y8WeK0bfoW67p0yQexwut2c/IsMDshdvckw9N3t/7IbRZr8d3rWha4/db7kWJtXvsJzp HsQMA X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 Update the page_vma_mapped_walk structure to track whether the pgoff being tracked is an anonymous pgoff or not and update the comments to reflect this. This is necessary in order to determine the correct VMA page offset in vma_address_end() when pvmw->nr_pages > 1. Also document that pvmw->pgoff is meaningless for pvmw->nr_pages == 1 and for KSM. Do not set this field where pgoff is not specified. This is laying the groundwork for eventually using anonymous page offsets as the index for all anonymous folios. No functional change intended. Signed-off-by: Lorenzo Stoakes (ARM) --- include/linux/rmap.h | 4 +++- mm/internal.h | 13 ++++++++----- mm/rmap.c | 2 ++ 3 files changed, 13 insertions(+), 6 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 8dc0871e5f00..0574537a355c 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -864,13 +864,14 @@ struct page *make_device_exclusive(struct mm_struct *mm, unsigned long addr, struct page_vma_mapped_walk { unsigned long pfn; unsigned long nr_pages; - pgoff_t pgoff; + pgoff_t pgoff; /* Only meaningful if nr_pages > 1 and not a KSM walk */ struct vm_area_struct *vma; unsigned long address; pmd_t *pmd; pte_t *pte; spinlock_t *ptl; unsigned int flags; + bool pgoff_is_anon : 1; }; #define DEFINE_FOLIO_VMA_WALK(name, _folio, _vma, _address, _flags) \ @@ -881,6 +882,7 @@ struct page_vma_mapped_walk { .vma = _vma, \ .address = _address, \ .flags = _flags, \ + .pgoff_is_anon = folio_test_anon(_folio), \ } static inline void page_vma_mapped_walk_done(struct page_vma_mapped_walk *pvmw) diff --git a/mm/internal.h b/mm/internal.h index 920872904bda..fbfa68d8ecc3 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1079,22 +1079,25 @@ static inline unsigned long vma_anon_address(const struct vm_area_struct *vma, } /* - * Then at what user virtual address will none of the range be found in vma? + * At what user virtual address will none of the range be found in vma? * Assumes that vma_address() already returned a good starting address. */ static inline unsigned long vma_address_end(struct page_vma_mapped_walk *pvmw) { - struct vm_area_struct *vma = pvmw->vma; - pgoff_t pgoff; + const struct vm_area_struct *vma = pvmw->vma; + const pgoff_t pgoff = pvmw->pgoff; + pgoff_t pgoff_vma_start; unsigned long address; + pgoff_t pgoff_end; /* Common case, plus ->pgoff is invalid for KSM */ if (pvmw->nr_pages == 1) return pvmw->address + PAGE_SIZE; - pgoff = pvmw->pgoff + pvmw->nr_pages; + pgoff_vma_start = vma_start_pgoff(vma); + pgoff_end = pgoff + pvmw->nr_pages; address = vma->vm_start + - ((pgoff - vma_start_pgoff(vma)) << PAGE_SHIFT); + ((pgoff_end - pgoff_vma_start) << PAGE_SHIFT); /* Check for address beyond vma (or wrapped through 0?) */ if (address < vma->vm_start || address > vma->vm_end) address = vma->vm_end; diff --git a/mm/rmap.c b/mm/rmap.c index 5798427d007f..ab3f879454de 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1240,6 +1240,7 @@ static bool mapping_wrprotect_range_one(struct folio *folio, .vma = vma, .address = address, .flags = PVMW_SYNC, + .pgoff_is_anon = false, }; state->cleaned += page_vma_mkclean_one(&pvmw); @@ -1317,6 +1318,7 @@ int pfn_mkclean_range(unsigned long pfn, unsigned long nr_pages, pgoff_t pgoff, .pgoff = pgoff, .vma = vma, .flags = PVMW_SYNC, + .pgoff_is_anon = false, }; if (invalid_mkclean_vma(vma, NULL)) -- 2.55.0