From: Andrew Morton <akpm@linux-foundation.org> To: David Hildenbrand <david@redhat.com> Cc: Alex Sierra <alex.sierra@amd.com>, jgg@nvidia.com, Felix.Kuehling@amd.com, linux-mm@kvack.org, rcampbell@nvidia.com, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, hch@lst.de, jglisse@redhat.com, apopple@nvidia.com, willy@infradead.org Subject: Re: [PATCH v7 03/14] mm: handling Non-LRU pages returned by vm_normal_pages Date: Wed, 29 Jun 2022 16:31:28 -0700 [thread overview] Message-ID: <20220629163128.7002f81b6346b2ed34d4d02a@linux-foundation.org> (raw) In-Reply-To: <269e4c6e-d6ee-bace-9fab-a9dcb4268d5a@redhat.com> On Wed, 29 Jun 2022 11:59:26 +0200 David Hildenbrand <david@redhat.com> wrote: > On 29.06.22 05:54, Alex Sierra wrote: > > With DEVICE_COHERENT, we'll soon have vm_normal_pages() return > > device-managed anonymous pages that are not LRU pages. Although they > > behave like normal pages for purposes of mapping in CPU page, and for > > COW. They do not support LRU lists, NUMA migration or THP. > > > > Callers to follow_page that expect LRU pages, are also checked for > > device zone pages due to DEVICE_COHERENT type. > > Can we rephrase that to (because zeropage) > > "Callers to follow_page() currently don't expect ZONE_DEVICE pages, > however, with DEVICE_COHERENT we might now return ZONE_DEVICE. Check for > ZONE_DEVICE pages in applicable users of follow_page() as well." I made that change to my copy. > > --- a/mm/memory.c > > +++ b/mm/memory.c > > @@ -624,6 +624,13 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, > > if (is_zero_pfn(pfn)) > > return NULL; > > if (pte_devmap(pte)) > > +/* > > + * NOTE: New uers of ZONE_DEVICE will not set pte_devmap() and will have > > s/uers/users/ > > > + * refcounts incremented on their struct pages when they are inserted into > > + * PTEs, thus they are safe to return here. Legacy ZONE_DEVICE pages that set > > + * pte_devmap() do not have refcounts. Example of legacy ZONE_DEVICE is > > + * MEMORY_DEVICE_FS_DAX type in pmem or virtio_fs drivers. > > + */ And let's regularize that comment placement? --- a/mm/memory.c~mm-handling-non-lru-pages-returned-by-vm_normal_pages-fix +++ a/mm/memory.c @@ -632,16 +632,16 @@ struct page *vm_normal_page(struct vm_ar return NULL; if (is_zero_pfn(pfn)) return NULL; + /* + * NOTE: New users of ZONE_DEVICE will not set pte_devmap() + * and will have refcounts incremented on their struct pages + * when they are inserted into PTEs, thus they are safe to + * return here. Legacy ZONE_DEVICE pages that set pte_devmap() + * do not have refcounts. Example of legacy ZONE_DEVICE is + * MEMORY_DEVICE_FS_DAX type in pmem or virtio_fs drivers. + */ if (pte_devmap(pte)) -/* - * NOTE: New uers of ZONE_DEVICE will not set pte_devmap() and will have - * refcounts incremented on their struct pages when they are inserted into - * PTEs, thus they are safe to return here. Legacy ZONE_DEVICE pages that set - * pte_devmap() do not have refcounts. Example of legacy ZONE_DEVICE is - * MEMORY_DEVICE_FS_DAX type in pmem or virtio_fs drivers. - */ return NULL; - print_bad_pte(vma, addr, pte, NULL); return NULL; } _
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@linux-foundation.org> To: David Hildenbrand <david@redhat.com> Cc: Alex Sierra <alex.sierra@amd.com>, rcampbell@nvidia.com, willy@infradead.org, Felix.Kuehling@amd.com, apopple@nvidia.com, amd-gfx@lists.freedesktop.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, jglisse@redhat.com, dri-devel@lists.freedesktop.org, jgg@nvidia.com, linux-ext4@vger.kernel.org, hch@lst.de Subject: Re: [PATCH v7 03/14] mm: handling Non-LRU pages returned by vm_normal_pages Date: Wed, 29 Jun 2022 16:31:28 -0700 [thread overview] Message-ID: <20220629163128.7002f81b6346b2ed34d4d02a@linux-foundation.org> (raw) In-Reply-To: <269e4c6e-d6ee-bace-9fab-a9dcb4268d5a@redhat.com> On Wed, 29 Jun 2022 11:59:26 +0200 David Hildenbrand <david@redhat.com> wrote: > On 29.06.22 05:54, Alex Sierra wrote: > > With DEVICE_COHERENT, we'll soon have vm_normal_pages() return > > device-managed anonymous pages that are not LRU pages. Although they > > behave like normal pages for purposes of mapping in CPU page, and for > > COW. They do not support LRU lists, NUMA migration or THP. > > > > Callers to follow_page that expect LRU pages, are also checked for > > device zone pages due to DEVICE_COHERENT type. > > Can we rephrase that to (because zeropage) > > "Callers to follow_page() currently don't expect ZONE_DEVICE pages, > however, with DEVICE_COHERENT we might now return ZONE_DEVICE. Check for > ZONE_DEVICE pages in applicable users of follow_page() as well." I made that change to my copy. > > --- a/mm/memory.c > > +++ b/mm/memory.c > > @@ -624,6 +624,13 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, > > if (is_zero_pfn(pfn)) > > return NULL; > > if (pte_devmap(pte)) > > +/* > > + * NOTE: New uers of ZONE_DEVICE will not set pte_devmap() and will have > > s/uers/users/ > > > + * refcounts incremented on their struct pages when they are inserted into > > + * PTEs, thus they are safe to return here. Legacy ZONE_DEVICE pages that set > > + * pte_devmap() do not have refcounts. Example of legacy ZONE_DEVICE is > > + * MEMORY_DEVICE_FS_DAX type in pmem or virtio_fs drivers. > > + */ And let's regularize that comment placement? --- a/mm/memory.c~mm-handling-non-lru-pages-returned-by-vm_normal_pages-fix +++ a/mm/memory.c @@ -632,16 +632,16 @@ struct page *vm_normal_page(struct vm_ar return NULL; if (is_zero_pfn(pfn)) return NULL; + /* + * NOTE: New users of ZONE_DEVICE will not set pte_devmap() + * and will have refcounts incremented on their struct pages + * when they are inserted into PTEs, thus they are safe to + * return here. Legacy ZONE_DEVICE pages that set pte_devmap() + * do not have refcounts. Example of legacy ZONE_DEVICE is + * MEMORY_DEVICE_FS_DAX type in pmem or virtio_fs drivers. + */ if (pte_devmap(pte)) -/* - * NOTE: New uers of ZONE_DEVICE will not set pte_devmap() and will have - * refcounts incremented on their struct pages when they are inserted into - * PTEs, thus they are safe to return here. Legacy ZONE_DEVICE pages that set - * pte_devmap() do not have refcounts. Example of legacy ZONE_DEVICE is - * MEMORY_DEVICE_FS_DAX type in pmem or virtio_fs drivers. - */ return NULL; - print_bad_pte(vma, addr, pte, NULL); return NULL; } _
next prev parent reply other threads:[~2022-06-29 23:31 UTC|newest] Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-06-29 3:54 [PATCH v7 00/14] Add MEMORY_DEVICE_COHERENT for coherent device memory mapping Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 3:54 ` [PATCH v7 01/14] mm: rename is_pinnable_pages to is_pinnable_longterm_pages Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 7:33 ` David Hildenbrand 2022-06-29 7:33 ` David Hildenbrand 2022-06-29 22:08 ` Felix Kuehling 2022-06-29 22:08 ` Felix Kuehling 2022-06-29 22:15 ` David Hildenbrand 2022-06-29 22:15 ` David Hildenbrand 2022-07-02 4:25 ` Andrew Morton 2022-07-02 4:25 ` Andrew Morton 2022-06-29 23:24 ` Andrew Morton 2022-06-29 23:24 ` Andrew Morton 2022-06-29 3:54 ` [PATCH v7 02/14] mm: add zone device coherent type memory support Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 18:48 ` David Hildenbrand 2022-06-29 18:48 ` David Hildenbrand 2022-06-29 3:54 ` [PATCH v7 03/14] mm: handling Non-LRU pages returned by vm_normal_pages Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 9:59 ` David Hildenbrand 2022-06-29 9:59 ` David Hildenbrand 2022-06-29 23:31 ` Andrew Morton [this message] 2022-06-29 23:31 ` Andrew Morton 2022-06-29 3:54 ` [PATCH v7 04/14] mm: add device coherent vma selection for memory migration Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-30 10:04 ` David Hildenbrand 2022-06-30 10:04 ` David Hildenbrand 2022-06-30 11:44 ` Alistair Popple 2022-06-30 11:44 ` Alistair Popple 2022-06-30 20:56 ` David Hildenbrand 2022-06-30 20:56 ` David Hildenbrand 2022-06-29 3:54 ` [PATCH v7 05/14] mm: remove the vma check in migrate_vma_setup() Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 3:54 ` [PATCH v7 06/14] mm/gup: migrate device coherent pages when pinning instead of failing Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 3:54 ` [PATCH v7 07/14] drm/amdkfd: add SPM support for SVM Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 3:54 ` [PATCH v7 08/14] lib: test_hmm add ioctl to get zone device type Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 3:54 ` [PATCH v7 09/14] lib: test_hmm add module param for " Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 3:54 ` [PATCH v7 10/14] lib: add support for device coherent type in test_hmm Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 3:54 ` [PATCH v7 11/14] tools: update hmm-test to support device coherent type Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 3:54 ` [PATCH v7 12/14] tools: update test_hmm script to support SP config Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 3:54 ` [PATCH v7 13/14] tools: add hmm gup tests for device coherent type Alex Sierra 2022-06-29 3:54 ` Alex Sierra 2022-06-29 3:54 ` [PATCH v7 14/14] tools: add selftests to hmm for COW in device memory Alex Sierra 2022-06-29 3:54 ` Alex Sierra
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20220629163128.7002f81b6346b2ed34d4d02a@linux-foundation.org \ --to=akpm@linux-foundation.org \ --cc=Felix.Kuehling@amd.com \ --cc=alex.sierra@amd.com \ --cc=amd-gfx@lists.freedesktop.org \ --cc=apopple@nvidia.com \ --cc=david@redhat.com \ --cc=dri-devel@lists.freedesktop.org \ --cc=hch@lst.de \ --cc=jgg@nvidia.com \ --cc=jglisse@redhat.com \ --cc=linux-ext4@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=linux-xfs@vger.kernel.org \ --cc=rcampbell@nvidia.com \ --cc=willy@infradead.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.