From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 806FDC47088 for ; Thu, 1 Dec 2022 00:02:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230280AbiLAACb (ORCPT ); Wed, 30 Nov 2022 19:02:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230184AbiLAAAx (ORCPT ); Wed, 30 Nov 2022 19:00:53 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A13687CBD for ; Wed, 30 Nov 2022 16:00:50 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C6324614D0 for ; Thu, 1 Dec 2022 00:00:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06F29C433B5; Thu, 1 Dec 2022 00:00:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1669852849; bh=WRxklQY0yrpPqpPATApRsaSEjuE8nJaCCNX0eIEfodY=; h=Date:To:From:Subject:From; b=qruepiLCV7LOlrBN4XbfdmSlZFNUJuBWW144fVzw4zYARoSt/q6BBXrkfjXA/hjoU dh/E4anqkIkahL3x4yfJ8NlcYufdkMQm12jTSs/iYH+j6sWI8bG81ES7JcL+opOH1q aOD4AgNLTm5+gNaxK2Qlqw3/IUlBWOSqv990UPio= Date: Wed, 30 Nov 2022 16:00:48 -0800 To: mm-commits@vger.kernel.org, ying.huang@intel.com, naoya.horiguchi@nec.com, linmiaohe@huawei.com, david@redhat.com, aarcange@redhat.com, peterx@redhat.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-use-pte-markers-for-swap-errors.patch removed from -mm tree Message-Id: <20221201000049.06F29C433B5@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: mm: use pte markers for swap errors has been removed from the -mm tree. Its filename was mm-use-pte-markers-for-swap-errors.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Peter Xu Subject: mm: use pte markers for swap errors Date: Sun, 30 Oct 2022 17:41:51 -0400 PTE markers are ideal mechanism for things like SWP_SWAPIN_ERROR. Using a whole swap entry type for this purpose can be an overkill, especially if we already have PTE markers. Define a new bit for swapin error and replace it with pte markers. Then we can safely drop SWP_SWAPIN_ERROR and give one device slot back to swap. We used to have SWP_SWAPIN_ERROR taking the page pfn as part of the swap entry, but it's never used. Neither do I see how it can be useful because normally the swapin failure should not be caused by a bad page but bad swap device. Drop it alongside. Link: https://lkml.kernel.org/r/20221030214151.402274-3-peterx@redhat.com Signed-off-by: Peter Xu Reviewed-by: Huang Ying Reviewed-by: Miaohe Lin Acked-by: David Hildenbrand Cc: Andrea Arcangeli Cc: Naoya Horiguchi Signed-off-by: Andrew Morton --- include/linux/swap.h | 6 +----- include/linux/swapops.h | 26 ++++++++++++++------------ mm/memory.c | 6 ++++-- mm/shmem.c | 2 +- mm/swapfile.c | 2 +- 5 files changed, 21 insertions(+), 21 deletions(-) --- a/include/linux/swap.h~mm-use-pte-markers-for-swap-errors +++ a/include/linux/swap.h @@ -55,10 +55,6 @@ static inline int current_is_kswapd(void * actions on faults. */ -#define SWP_SWAPIN_ERROR_NUM 1 -#define SWP_SWAPIN_ERROR (MAX_SWAPFILES + SWP_HWPOISON_NUM + \ - SWP_MIGRATION_NUM + SWP_DEVICE_NUM + \ - SWP_PTE_MARKER_NUM) /* * PTE markers are used to persist information onto PTEs that otherwise * should be a none pte. As its name "PTE" hints, it should only be @@ -121,7 +117,7 @@ static inline int current_is_kswapd(void #define MAX_SWAPFILES \ ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \ SWP_MIGRATION_NUM - SWP_HWPOISON_NUM - \ - SWP_PTE_MARKER_NUM - SWP_SWAPIN_ERROR_NUM) + SWP_PTE_MARKER_NUM) /* * Magic header for a swap area. The first part of the union is --- a/include/linux/swapops.h~mm-use-pte-markers-for-swap-errors +++ a/include/linux/swapops.h @@ -162,16 +162,6 @@ static inline void *swp_to_radix_entry(s return xa_mk_value(entry.val); } -static inline swp_entry_t make_swapin_error_entry(struct page *page) -{ - return swp_entry(SWP_SWAPIN_ERROR, page_to_pfn(page)); -} - -static inline int is_swapin_error_entry(swp_entry_t entry) -{ - return swp_type(entry) == SWP_SWAPIN_ERROR; -} - #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset) { @@ -409,8 +399,9 @@ static inline bool is_migration_entry_di typedef unsigned long pte_marker; -#define PTE_MARKER_UFFD_WP BIT(0) -#define PTE_MARKER_MASK (PTE_MARKER_UFFD_WP) +#define PTE_MARKER_UFFD_WP BIT(0) +#define PTE_MARKER_SWAPIN_ERROR BIT(1) +#define PTE_MARKER_MASK (BIT(2) - 1) static inline swp_entry_t make_pte_marker_entry(pte_marker marker) { @@ -437,6 +428,17 @@ static inline pte_t make_pte_marker(pte_ return swp_entry_to_pte(make_pte_marker_entry(marker)); } +static inline swp_entry_t make_swapin_error_entry(void) +{ + return make_pte_marker_entry(PTE_MARKER_SWAPIN_ERROR); +} + +static inline int is_swapin_error_entry(swp_entry_t entry) +{ + return is_pte_marker_entry(entry) && + (pte_marker_get(entry) & PTE_MARKER_SWAPIN_ERROR); +} + /* * This is a special version to check pte_none() just to cover the case when * the pte is a pte marker. It existed because in many cases the pte marker --- a/mm/memory.c~mm-use-pte-markers-for-swap-errors +++ a/mm/memory.c @@ -3668,6 +3668,10 @@ static vm_fault_t handle_pte_marker(stru if (WARN_ON_ONCE(!marker)) return VM_FAULT_SIGBUS; + /* Higher priority than uffd-wp when data corrupted */ + if (marker & PTE_MARKER_SWAPIN_ERROR) + return VM_FAULT_SIGBUS; + if (pte_marker_entry_uffd_wp(entry)) return pte_marker_handle_uffd_wp(vmf); @@ -3727,8 +3731,6 @@ vm_fault_t do_swap_page(struct vm_fault put_page(vmf->page); } else if (is_hwpoison_entry(entry)) { ret = VM_FAULT_HWPOISON; - } else if (is_swapin_error_entry(entry)) { - ret = VM_FAULT_SIGBUS; } else if (is_pte_marker_entry(entry)) { ret = handle_pte_marker(vmf); } else { --- a/mm/shmem.c~mm-use-pte-markers-for-swap-errors +++ a/mm/shmem.c @@ -1682,7 +1682,7 @@ static void shmem_set_folio_swapin_error swp_entry_t swapin_error; void *old; - swapin_error = make_swapin_error_entry(&folio->page); + swapin_error = make_swapin_error_entry(); old = xa_cmpxchg_irq(&mapping->i_pages, index, swp_to_radix_entry(swap), swp_to_radix_entry(swapin_error), 0); --- a/mm/swapfile.c~mm-use-pte-markers-for-swap-errors +++ a/mm/swapfile.c @@ -1781,7 +1781,7 @@ static int unuse_pte(struct vm_area_stru pte_t pteval; dec_mm_counter(vma->vm_mm, MM_SWAPENTS); - pteval = swp_entry_to_pte(make_swapin_error_entry(page)); + pteval = swp_entry_to_pte(make_swapin_error_entry()); set_pte_at(vma->vm_mm, addr, pte, pteval); swap_free(entry); ret = 0; _ Patches currently in -mm which might be from peterx@redhat.com are mm-migrate-fix-read-only-page-got-writable-when-recover-pte.patch mm-hugetlb-let-vma_offset_start-to-return-start.patch mm-hugetlb-dont-wait-for-migration-entry-during-follow-page.patch mm-hugetlb-document-huge_pte_offset-usage.patch mm-hugetlb-move-swap-entry-handling-into-vma-lock-when-faulted.patch mm-hugetlb-make-userfaultfd_huge_must_wait-safe-to-pmd-unshare.patch mm-hugetlb-make-hugetlb_follow_page_mask-safe-to-pmd-unshare.patch mm-hugetlb-make-follow_hugetlb_page-safe-to-pmd-unshare.patch mm-hugetlb-make-walk_hugetlb_range-safe-to-pmd-unshare.patch mm-hugetlb-make-page_vma_mapped_walk-safe-to-pmd-unshare.patch mm-hugetlb-introduce-hugetlb_walk.patch mm-hugetlb-introduce-hugetlb_walk-fix.patch mm-hugetlb-introduce-hugetlb_walk-fix-2.patch