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 4FEC71367 for ; Tue, 17 Jun 2025 00:00:46 +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=1750118446; cv=none; b=UG7OjBnRHOiIpuPxN+lZLr2oauy+j1hXimWTzZS4vJM0ntoAE8wTUlFXrqyQ42mq4jMRwHOIvx2lfSX1Gwz5K34yB40nepBq6vY0jpCF+EOaTHct8/ulbCbAuMaA+YNhiaELh4B7SWamL+uiPeqEDFz9VvOuVeI1x8WsKcLnZ/k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750118446; c=relaxed/simple; bh=N6jkSE5sm5u85HJi/4ZTZA6YUZD9ntpTSROewEbeRI4=; h=Date:To:From:Subject:Message-Id; b=CDgRdKffCFgt2y6vv6y9DltXdSDZcLSNw3a4gljEWAKZvvFuRhovg0BYypdMLgqCIScovxS41WetGxtToeYV5alpY7QmUWZVXwT1dFy3MPcnX7nhZVApdGoddL/krOV5yq7x26cLzO7oCU4GVUSnCNRjPU5j3pQSthNTVZsjWhA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=JHF+DoH3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="JHF+DoH3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD113C4CEEF; Tue, 17 Jun 2025 00:00:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1750118445; bh=N6jkSE5sm5u85HJi/4ZTZA6YUZD9ntpTSROewEbeRI4=; h=Date:To:From:Subject:From; b=JHF+DoH3APH2NYfXliYPDBOiDGWq9qTyxhdOrO/shRiaXY8V1w93RUoz6x6E2V4q2 dumUnBFQj2KeyYDe7TpMZmZcmLkA61eUriqyQHV5TfnAVCz+JOaVtmXIUaTk3L05WK ukAqCILnftNg+eOLrd+6UlEoctrQh5HRn/QfmiAw= Date: Mon, 16 Jun 2025 17:00:45 -0700 To: mm-commits@vger.kernel.org,zhang.lyra@gmail.com,willy@infradead.org,will@kernel.org,m.szyprowski@samsung.com,lorenzo.stoakes@oracle.com,john@groves.net,jhubbard@nvidia.com,jgg@nvidia.com,hch@lst.de,gerald.schaefer@linux.ibm.com,debug@rivosinc.com,david@redhat.com,dan.j.williams@intel.com,bjorn@rivosinc.com,bjorn@kernel.org,balbirs@nvidia.com,apopple@nvidia.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-convert-pxd_devmap-checks-to-vma_is_dax.patch added to mm-new branch Message-Id: <20250617000045.CD113C4CEEF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: convert pXd_devmap checks to vma_is_dax has been added to the -mm mm-new branch. Its filename is mm-convert-pxd_devmap-checks-to-vma_is_dax.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-convert-pxd_devmap-checks-to-vma_is_dax.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Alistair Popple Subject: mm: convert pXd_devmap checks to vma_is_dax Date: Mon, 16 Jun 2025 21:58:03 +1000 All users of dax now require a ZONE_DEVICE page which is properly refcounted. This means there is no longer any need for the PFN_DEV, PFN_MAP and PFN_SPECIAL flags. Furthermore the PFN_SG_CHAIN and PFN_SG_LAST flags never appear to have been used. It is therefore possible to remove the pfn_t type and replace any usage with raw pfns. The remaining users of PFN_DEV have simply passed this to vmf_insert_mixed() to create pte_devmap() mappings. It is unclear why this was the case but presumably to ensure vm_normal_page() does not return these pages. These users can be trivially converted to raw pfns and creating a pXX_special() mapping to ensure vm_normal_page() still doesn't return these pages. Now that there are no users of PFN_DEV we can remove the devmap page table bit and all associated functions and macros, freeing up a software page table bit. This patch (of 14): Currently dax is the only user of pmd and pud mapped ZONE_DEVICE pages. Therefore page walkers that want to exclude DAX pages can check pmd_devmap or pud_devmap. However soon dax will no longer set PFN_DEV, meaning dax pages are mapped as normal pages. Ensure page walkers that currently use pXd_devmap to skip DAX pages continue to do so by adding explicit checks of the VMA instead. Link: https://lkml.kernel.org/r/361009510f346090fad328c53ec228d99bb955ee.1750075065.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple Reviewed-by: Jason Gunthorpe Reviewed-by: Dan Williams Cc: Balbir Singh Cc: Björn Töpel Cc: Christoph Hellwig Cc: Chunyan Zhang Cc: David Hildenbrand Cc: Deepak Gupta Cc: Gerald Schaefer Cc: Inki Dae Cc: John Groves Cc: John Hubbard Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Björn Töpel Cc: Will Deacon Signed-off-by: Andrew Morton --- fs/userfaultfd.c | 2 +- mm/hmm.c | 2 +- mm/userfaultfd.c | 6 ------ 3 files changed, 2 insertions(+), 8 deletions(-) --- a/fs/userfaultfd.c~mm-convert-pxd_devmap-checks-to-vma_is_dax +++ a/fs/userfaultfd.c @@ -304,7 +304,7 @@ again: goto out; ret = false; - if (!pmd_present(_pmd) || pmd_devmap(_pmd)) + if (!pmd_present(_pmd) || vma_is_dax(vmf->vma)) goto out; if (pmd_trans_huge(_pmd)) { --- a/mm/hmm.c~mm-convert-pxd_devmap-checks-to-vma_is_dax +++ a/mm/hmm.c @@ -441,7 +441,7 @@ static int hmm_vma_walk_pud(pud_t *pudp, return hmm_vma_walk_hole(start, end, -1, walk); } - if (pud_leaf(pud) && pud_devmap(pud)) { + if (pud_leaf(pud) && vma_is_dax(walk->vma)) { unsigned long i, npages, pfn; unsigned int required_fault; unsigned long *hmm_pfns; --- a/mm/userfaultfd.c~mm-convert-pxd_devmap-checks-to-vma_is_dax +++ a/mm/userfaultfd.c @@ -1818,12 +1818,6 @@ ssize_t move_pages(struct userfaultfd_ct ptl = pmd_trans_huge_lock(src_pmd, src_vma); if (ptl) { - if (pmd_devmap(*src_pmd)) { - spin_unlock(ptl); - err = -ENOENT; - break; - } - /* Check if we can move the pmd without splitting it. */ if (move_splits_huge_pmd(dst_addr, src_addr, src_start + len) || !pmd_none(dst_pmdval)) { _ Patches currently in -mm which might be from apopple@nvidia.com are mm-convert-pxd_devmap-checks-to-vma_is_dax.patch mm-filter-zone-device-pages-returned-from-folio_walk_start.patch mm-convert-vmf_insert_mixed-from-using-pte_devmap-to-pte_special.patch mm-remove-remaining-uses-of-pfn_dev.patch mm-gup-remove-pxx_devmap-usage-from-get_user_pages.patch mm-huge_memory-remove-pxd_devmap-usage-from-insert_pxd_pfn.patch mm-remove-redundant-pxd_devmap-calls.patch mm-khugepaged-remove-redundant-pmd_devmap-check.patch powerpc-remove-checks-for-devmap-pages-and-pmds-puds.patch fs-dax-remove-fs_dax_limited-config-option.patch mm-remove-devmap-related-functions-and-page-table-bits.patch mm-remove-pfn_map-pfn_special-pfn_sg_chain-and-pfn_sg_last.patch mm-remove-callers-of-pfn_t-functionality.patch mm-memremap-remove-unused-devmap_managed_key.patch