This is our MEMORY_DEVICE_COHERENT patch series rebased and updated
for current 5.18-rc7.
Changes since the last version:
- Fixed problems with migration during long-term pinning in
get_user_pages
- Open coded vm_normal_lru_pages as suggested in previous code review
- Update hmm_gup_test with more get_user_pages calls, include
hmm_cow_in_device in hmm-test.
This patch series introduces MEMORY_DEVICE_COHERENT, a type of memory
owned by a device that can be mapped into CPU page tables like
MEMORY_DEVICE_GENERIC and can also be migrated like
MEMORY_DEVICE_PRIVATE.
This patch series is mostly self-contained except for a few places where
it needs to update other subsystems to handle the new memory type.
System stability and performance are not affected according to our
ongoing testing, including xfstests.
How it works: The system BIOS advertises the GPU device memory
(aka VRAM) as SPM (special purpose memory) in the UEFI system address
map.
The amdgpu driver registers the memory with devmap as
MEMORY_DEVICE_COHERENT using devm_memremap_pages. The initial user for
this hardware page migration capability is the Frontier supercomputer
project. This functionality is not AMD-specific. We expect other GPU
vendors to find this functionality useful, and possibly other hardware
types in the future.
Our test nodes in the lab are similar to the Frontier configuration,
with .5 TB of system memory plus 256 GB of device memory split across
4 GPUs, all in a single coherent address space. Page migration is
expected to improve application efficiency significantly. We will
report empirical results as they become available.
Coherent device type pages at gup are now migrated back to system
memory if they are being pinned long-term (FOLL_LONGTERM). The reason
is, that long-term pinning would interfere with the device memory
manager owning the device-coherent pages (e.g. evictions in TTM).
These series incorporate Alistair Popple patches to do this
migration from pin_user_pages() calls. hmm_gup_test has been added to
hmm-test to test different get user pages calls.
This series includes handling of device-managed anonymous pages
returned by vm_normal_pages. Although they behave like normal pages
for purposes of mapping in CPU page tables and for COW, they do not
support LRU lists, NUMA migration or THP.
We also introduced a FOLL_LRU flag that adds the same behaviour to
follow_page and related APIs, to allow callers to specify that they
expect to put pages on an LRU list.
v2:
- Rebase to latest 5.18-rc7.
- Drop patch "mm: add device coherent checker to remove migration pte"
and modify try_to_migrate_one, to let DEVICE_COHERENT pages fall
through to normal page path. Based on Alistair Popple's comment.
- Fix comment formatting.
- Reword comment in vm_normal_page about pte_devmap().
- Merge "drm/amdkfd: coherent type as sys mem on migration to ram" to
"drm/amdkfd: add SPM support for SVM".
Alex Sierra (11):
mm: add zone device coherent type memory support
mm: add device coherent vma selection for memory migration
drm/amdkfd: add SPM support for SVM
lib: test_hmm add ioctl to get zone device type
lib: test_hmm add module param for zone device type
lib: add support for device coherent type in test_hmm
tools: update hmm-test to support device coherent type
tools: update test_hmm script to support SP config
mm: handling Non-LRU pages returned by vm_normal_pages
tools: add hmm gup tests for device coherent type
tools: add selftests to hmm for COW in device memory
Alistair Popple (2):
mm: remove the vma check in migrate_vma_setup()
mm/gup: migrate device coherent pages when pinning instead of failing
drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 33 ++-
fs/proc/task_mmu.c | 2 +-
include/linux/memremap.h | 19 ++
include/linux/migrate.h | 1 +
include/linux/mm.h | 3 +-
lib/test_hmm.c | 349 +++++++++++++++++------
lib/test_hmm_uapi.h | 22 +-
mm/gup.c | 49 +++-
mm/huge_memory.c | 2 +-
mm/internal.h | 1 +
mm/khugepaged.c | 9 +-
mm/ksm.c | 6 +-
mm/madvise.c | 4 +-
mm/memcontrol.c | 7 +-
mm/memory-failure.c | 8 +-
mm/memory.c | 9 +-
mm/mempolicy.c | 2 +-
mm/memremap.c | 10 +
mm/migrate.c | 4 +-
mm/migrate_device.c | 115 ++++++--
mm/mlock.c | 2 +-
mm/mprotect.c | 2 +-
mm/rmap.c | 5 +-
tools/testing/selftests/vm/hmm-tests.c | 308 ++++++++++++++++++--
tools/testing/selftests/vm/test_hmm.sh | 24 +-
25 files changed, 814 insertions(+), 182 deletions(-)
--
2.32.0
This case is used to migrate pages from device memory, back to system
memory. Device coherent type memory is cache coherent from device and CPU
point of view.
Signed-off-by: Alex Sierra <[email protected]>
Acked-by: Felix Kuehling <[email protected]>
Reviewed-by: Alistair Poppple <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
---
include/linux/migrate.h | 1 +
mm/migrate_device.c | 12 +++++++++---
2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 90e75d5a54d6..a4a336fd81fc 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -138,6 +138,7 @@ static inline unsigned long migrate_pfn(unsigned long pfn)
enum migrate_vma_direction {
MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
+ MIGRATE_VMA_SELECT_DEVICE_COHERENT = 1 << 2,
};
struct migrate_vma {
diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index 7e267142ea34..a0b997935cf9 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -148,15 +148,21 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
if (is_writable_device_private_entry(entry))
mpfn |= MIGRATE_PFN_WRITE;
} else {
- if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
- goto next;
pfn = pte_pfn(pte);
- if (is_zero_pfn(pfn)) {
+ if (is_zero_pfn(pfn) &&
+ (migrate->flags & MIGRATE_VMA_SELECT_SYSTEM)) {
mpfn = MIGRATE_PFN_MIGRATE;
migrate->cpages++;
goto next;
}
page = vm_normal_page(migrate->vma, addr, pte);
+ if (page && !is_zone_device_page(page) &&
+ !(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
+ goto next;
+ else if (page && is_device_coherent_page(page) &&
+ (!(migrate->flags & MIGRATE_VMA_SELECT_DEVICE_COHERENT) ||
+ page->pgmap->owner != migrate->pgmap_owner))
+ goto next;
mpfn = migrate_pfn(pfn) | MIGRATE_PFN_MIGRATE;
mpfn |= pte_write(pte) ? MIGRATE_PFN_WRITE : 0;
}
--
2.32.0
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.
We also introduced a FOLL_LRU flag that adds the same behaviour to
follow_page and related APIs, to allow callers to specify that they
expect to put pages on an LRU list.
Signed-off-by: Alex Sierra <[email protected]>
Acked-by: Felix Kuehling <[email protected]>
---
fs/proc/task_mmu.c | 2 +-
include/linux/mm.h | 3 ++-
mm/gup.c | 2 ++
mm/huge_memory.c | 2 +-
mm/khugepaged.c | 9 ++++++---
mm/ksm.c | 6 +++---
mm/madvise.c | 4 ++--
mm/memory.c | 9 ++++++++-
mm/mempolicy.c | 2 +-
mm/migrate.c | 4 ++--
mm/mlock.c | 2 +-
mm/mprotect.c | 2 +-
12 files changed, 30 insertions(+), 17 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f46060eb91b5..5d620733f173 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1785,7 +1785,7 @@ static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
return NULL;
page = vm_normal_page(vma, addr, pte);
- if (!page)
+ if (!page || is_zone_device_page(page))
return NULL;
if (PageReserved(page))
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9f44254af8ce..d7f253a0c41e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -601,7 +601,7 @@ struct vm_operations_struct {
#endif
/*
* Called by vm_normal_page() for special PTEs to find the
- * page for @addr. This is useful if the default behavior
+ * page for @addr. This is useful if the default behavior
* (using pte_page()) would not find the correct page.
*/
struct page *(*find_special_page)(struct vm_area_struct *vma,
@@ -2929,6 +2929,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
#define FOLL_NUMA 0x200 /* force NUMA hinting page fault */
#define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */
#define FOLL_TRIED 0x800 /* a retry, previous pass started an IO */
+#define FOLL_LRU 0x1000 /* return only LRU (anon or page cache) */
#define FOLL_REMOTE 0x2000 /* we are working on non-current tsk/mm */
#define FOLL_COW 0x4000 /* internal GUP flag */
#define FOLL_ANON 0x8000 /* don't do file mappings */
diff --git a/mm/gup.c b/mm/gup.c
index a214c8df7140..13bf04bce132 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -479,6 +479,8 @@ static struct page *follow_page_pte(struct vm_area_struct *vma,
}
page = vm_normal_page(vma, address, pte);
+ if ((flags & FOLL_LRU) && page && is_zone_device_page(page))
+ page = NULL;
if (!page && pte_devmap(pte) && (flags & (FOLL_GET | FOLL_PIN))) {
/*
* Only return device mapping pages in the FOLL_GET or FOLL_PIN
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 910a138e9859..eed80696c5fd 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2856,7 +2856,7 @@ static int split_huge_pages_pid(int pid, unsigned long vaddr_start,
}
/* FOLL_DUMP to ignore special (like zero) pages */
- page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP);
+ page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP | FOLL_LRU);
if (IS_ERR(page))
continue;
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index a4e5eaf3eb01..eb3cfd679800 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -627,7 +627,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
goto out;
}
page = vm_normal_page(vma, address, pteval);
- if (unlikely(!page)) {
+ if (unlikely(!page) || unlikely(is_zone_device_page(page))) {
result = SCAN_PAGE_NULL;
goto out;
}
@@ -1276,7 +1276,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
writable = true;
page = vm_normal_page(vma, _address, pteval);
- if (unlikely(!page)) {
+ if (unlikely(!page) || unlikely(is_zone_device_page(page))) {
result = SCAN_PAGE_NULL;
goto out_unmap;
}
@@ -1484,7 +1484,8 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr)
goto abort;
page = vm_normal_page(vma, addr, *pte);
-
+ if (page && is_zone_device_page(page))
+ page = NULL;
/*
* Note that uprobe, debugger, or MAP_PRIVATE may change the
* page table, but the new page will not be a subpage of hpage.
@@ -1502,6 +1503,8 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr)
if (pte_none(*pte))
continue;
page = vm_normal_page(vma, addr, *pte);
+ if (page && is_zone_device_page(page))
+ goto abort;
page_remove_rmap(page, vma, false);
}
diff --git a/mm/ksm.c b/mm/ksm.c
index 063a48eeb5ee..f16056efca21 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -474,7 +474,7 @@ static int break_ksm(struct vm_area_struct *vma, unsigned long addr)
do {
cond_resched();
page = follow_page(vma, addr,
- FOLL_GET | FOLL_MIGRATION | FOLL_REMOTE);
+ FOLL_GET | FOLL_MIGRATION | FOLL_REMOTE | FOLL_LRU);
if (IS_ERR_OR_NULL(page))
break;
if (PageKsm(page))
@@ -559,7 +559,7 @@ static struct page *get_mergeable_page(struct rmap_item *rmap_item)
if (!vma)
goto out;
- page = follow_page(vma, addr, FOLL_GET);
+ page = follow_page(vma, addr, FOLL_GET | FOLL_LRU);
if (IS_ERR_OR_NULL(page))
goto out;
if (PageAnon(page)) {
@@ -2288,7 +2288,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
while (ksm_scan.address < vma->vm_end) {
if (ksm_test_exit(mm))
break;
- *page = follow_page(vma, ksm_scan.address, FOLL_GET);
+ *page = follow_page(vma, ksm_scan.address, FOLL_GET | FOLL_LRU);
if (IS_ERR_OR_NULL(*page)) {
ksm_scan.address += PAGE_SIZE;
cond_resched();
diff --git a/mm/madvise.c b/mm/madvise.c
index 1873616a37d2..e9c24c834e98 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -413,7 +413,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd,
continue;
page = vm_normal_page(vma, addr, ptent);
- if (!page)
+ if (!page || is_zone_device_page(page))
continue;
/*
@@ -628,7 +628,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr,
}
page = vm_normal_page(vma, addr, ptent);
- if (!page)
+ if (!page || is_zone_device_page(page))
continue;
/*
diff --git a/mm/memory.c b/mm/memory.c
index 76e3af9639d9..571a26805ee1 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -621,6 +621,13 @@ 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
+ * 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);
@@ -4422,7 +4429,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
pte = pte_modify(old_pte, vma->vm_page_prot);
page = vm_normal_page(vma, vmf->address, pte);
- if (!page)
+ if (!page || is_zone_device_page(page))
goto out_map;
/* TODO: handle PTE-mapped THP */
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 8c74107a2b15..e32edbecb0cd 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -528,7 +528,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
if (!pte_present(*pte))
continue;
page = vm_normal_page(vma, addr, *pte);
- if (!page)
+ if (!page || is_zone_device_page(page))
continue;
/*
* vm_normal_page() filters out zero pages, but there might
diff --git a/mm/migrate.c b/mm/migrate.c
index 6c31ee1e1c9b..c5d50e96ecd7 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1611,7 +1611,7 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
goto out;
/* FOLL_DUMP to ignore special (like zero) pages */
- page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP);
+ page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP | FOLL_LRU);
err = PTR_ERR(page);
if (IS_ERR(page))
@@ -1802,7 +1802,7 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
goto set_status;
/* FOLL_DUMP to ignore special (like zero) pages */
- page = follow_page(vma, addr, FOLL_DUMP);
+ page = follow_page(vma, addr, FOLL_DUMP | FOLL_LRU);
err = PTR_ERR(page);
if (IS_ERR(page))
diff --git a/mm/mlock.c b/mm/mlock.c
index 716caf851043..b14e929084cc 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -333,7 +333,7 @@ static int mlock_pte_range(pmd_t *pmd, unsigned long addr,
if (!pte_present(*pte))
continue;
page = vm_normal_page(vma, addr, *pte);
- if (!page)
+ if (!page || is_zone_device_page(page))
continue;
if (PageTransCompound(page))
continue;
diff --git a/mm/mprotect.c b/mm/mprotect.c
index b69ce7a7b2b7..a6f3587ea29a 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -91,7 +91,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
continue;
page = vm_normal_page(vma, addr, oldpte);
- if (!page || PageKsm(page))
+ if (!page || is_zone_device_page(page) || PageKsm(page))
continue;
/* Also skip shared copy-on-write pages */
--
2.32.0
Test cases such as migrate_fault and migrate_multiple, were modified to
explicit migrate from device to sys memory without the need of page
faults, when using device coherent type.
Snapshot test case updated to read memory device type first and based
on that, get the proper returned results migrate_ping_pong test case
added to test explicit migration from device to sys memory for both
private and coherent zone types.
Helpers to migrate from device to sys memory and vicerversa
were also added.
Signed-off-by: Alex Sierra <[email protected]>
Acked-by: Felix Kuehling <[email protected]>
Reviewed-by: Alistair Popple <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
---
tools/testing/selftests/vm/hmm-tests.c | 123 ++++++++++++++++++++-----
1 file changed, 102 insertions(+), 21 deletions(-)
diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
index 203323967b50..84ec8c4a1dc7 100644
--- a/tools/testing/selftests/vm/hmm-tests.c
+++ b/tools/testing/selftests/vm/hmm-tests.c
@@ -44,6 +44,14 @@ struct hmm_buffer {
int fd;
uint64_t cpages;
uint64_t faults;
+ int zone_device_type;
+};
+
+enum {
+ HMM_PRIVATE_DEVICE_ONE,
+ HMM_PRIVATE_DEVICE_TWO,
+ HMM_COHERENCE_DEVICE_ONE,
+ HMM_COHERENCE_DEVICE_TWO,
};
#define TWOMEG (1 << 21)
@@ -60,6 +68,21 @@ FIXTURE(hmm)
unsigned int page_shift;
};
+FIXTURE_VARIANT(hmm)
+{
+ int device_number;
+};
+
+FIXTURE_VARIANT_ADD(hmm, hmm_device_private)
+{
+ .device_number = HMM_PRIVATE_DEVICE_ONE,
+};
+
+FIXTURE_VARIANT_ADD(hmm, hmm_device_coherent)
+{
+ .device_number = HMM_COHERENCE_DEVICE_ONE,
+};
+
FIXTURE(hmm2)
{
int fd0;
@@ -68,6 +91,24 @@ FIXTURE(hmm2)
unsigned int page_shift;
};
+FIXTURE_VARIANT(hmm2)
+{
+ int device_number0;
+ int device_number1;
+};
+
+FIXTURE_VARIANT_ADD(hmm2, hmm2_device_private)
+{
+ .device_number0 = HMM_PRIVATE_DEVICE_ONE,
+ .device_number1 = HMM_PRIVATE_DEVICE_TWO,
+};
+
+FIXTURE_VARIANT_ADD(hmm2, hmm2_device_coherent)
+{
+ .device_number0 = HMM_COHERENCE_DEVICE_ONE,
+ .device_number1 = HMM_COHERENCE_DEVICE_TWO,
+};
+
static int hmm_open(int unit)
{
char pathname[HMM_PATH_MAX];
@@ -81,12 +122,19 @@ static int hmm_open(int unit)
return fd;
}
+static bool hmm_is_coherent_type(int dev_num)
+{
+ return (dev_num >= HMM_COHERENCE_DEVICE_ONE);
+}
+
FIXTURE_SETUP(hmm)
{
self->page_size = sysconf(_SC_PAGE_SIZE);
self->page_shift = ffs(self->page_size) - 1;
- self->fd = hmm_open(0);
+ self->fd = hmm_open(variant->device_number);
+ if (self->fd < 0 && hmm_is_coherent_type(variant->device_number))
+ SKIP(exit(0), "DEVICE_COHERENT not available");
ASSERT_GE(self->fd, 0);
}
@@ -95,9 +143,11 @@ FIXTURE_SETUP(hmm2)
self->page_size = sysconf(_SC_PAGE_SIZE);
self->page_shift = ffs(self->page_size) - 1;
- self->fd0 = hmm_open(0);
+ self->fd0 = hmm_open(variant->device_number0);
+ if (self->fd0 < 0 && hmm_is_coherent_type(variant->device_number0))
+ SKIP(exit(0), "DEVICE_COHERENT not available");
ASSERT_GE(self->fd0, 0);
- self->fd1 = hmm_open(1);
+ self->fd1 = hmm_open(variant->device_number1);
ASSERT_GE(self->fd1, 0);
}
@@ -144,6 +194,7 @@ static int hmm_dmirror_cmd(int fd,
}
buffer->cpages = cmd.cpages;
buffer->faults = cmd.faults;
+ buffer->zone_device_type = cmd.zone_device_type;
return 0;
}
@@ -211,6 +262,20 @@ static void hmm_nanosleep(unsigned int n)
nanosleep(&t, NULL);
}
+static int hmm_migrate_sys_to_dev(int fd,
+ struct hmm_buffer *buffer,
+ unsigned long npages)
+{
+ return hmm_dmirror_cmd(fd, HMM_DMIRROR_MIGRATE_TO_DEV, buffer, npages);
+}
+
+static int hmm_migrate_dev_to_sys(int fd,
+ struct hmm_buffer *buffer,
+ unsigned long npages)
+{
+ return hmm_dmirror_cmd(fd, HMM_DMIRROR_MIGRATE_TO_SYS, buffer, npages);
+}
+
/*
* Simple NULL test of device open/close.
*/
@@ -875,7 +940,7 @@ TEST_F(hmm, migrate)
ptr[i] = i;
/* Migrate memory to device. */
- ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, npages);
@@ -923,7 +988,7 @@ TEST_F(hmm, migrate_fault)
ptr[i] = i;
/* Migrate memory to device. */
- ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, npages);
@@ -936,7 +1001,7 @@ TEST_F(hmm, migrate_fault)
ASSERT_EQ(ptr[i], i);
/* Migrate memory to the device again. */
- ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, npages);
@@ -976,7 +1041,7 @@ TEST_F(hmm, migrate_shared)
ASSERT_NE(buffer->ptr, MAP_FAILED);
/* Migrate memory to device. */
- ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
ASSERT_EQ(ret, -ENOENT);
hmm_buffer_free(buffer);
@@ -1015,7 +1080,7 @@ TEST_F(hmm2, migrate_mixed)
p = buffer->ptr;
/* Migrating a protected area should be an error. */
- ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, npages);
+ ret = hmm_migrate_sys_to_dev(self->fd1, buffer, npages);
ASSERT_EQ(ret, -EINVAL);
/* Punch a hole after the first page address. */
@@ -1023,7 +1088,7 @@ TEST_F(hmm2, migrate_mixed)
ASSERT_EQ(ret, 0);
/* We expect an error if the vma doesn't cover the range. */
- ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, 3);
+ ret = hmm_migrate_sys_to_dev(self->fd1, buffer, 3);
ASSERT_EQ(ret, -EINVAL);
/* Page 2 will be a read-only zero page. */
@@ -1055,13 +1120,13 @@ TEST_F(hmm2, migrate_mixed)
/* Now try to migrate pages 2-5 to device 1. */
buffer->ptr = p + 2 * self->page_size;
- ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, 4);
+ ret = hmm_migrate_sys_to_dev(self->fd1, buffer, 4);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, 4);
/* Page 5 won't be migrated to device 0 because it's on device 1. */
buffer->ptr = p + 5 * self->page_size;
- ret = hmm_dmirror_cmd(self->fd0, HMM_DMIRROR_MIGRATE, buffer, 1);
+ ret = hmm_migrate_sys_to_dev(self->fd0, buffer, 1);
ASSERT_EQ(ret, -ENOENT);
buffer->ptr = p;
@@ -1070,8 +1135,12 @@ TEST_F(hmm2, migrate_mixed)
}
/*
- * Migrate anonymous memory to device private memory and fault it back to system
- * memory multiple times.
+ * Migrate anonymous memory to device memory and back to system memory
+ * multiple times. In case of private zone configuration, this is done
+ * through fault pages accessed by CPU. In case of coherent zone configuration,
+ * the pages from the device should be explicitly migrated back to system memory.
+ * The reason is Coherent device zone has coherent access by CPU, therefore
+ * it will not generate any page fault.
*/
TEST_F(hmm, migrate_multiple)
{
@@ -1107,8 +1176,7 @@ TEST_F(hmm, migrate_multiple)
ptr[i] = i;
/* Migrate memory to device. */
- ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer,
- npages);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, npages);
@@ -1116,7 +1184,13 @@ TEST_F(hmm, migrate_multiple)
for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
ASSERT_EQ(ptr[i], i);
- /* Fault pages back to system memory and check them. */
+ /* Migrate back to system memory and check them. */
+ if (hmm_is_coherent_type(variant->device_number)) {
+ ret = hmm_migrate_dev_to_sys(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+ }
+
for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
ASSERT_EQ(ptr[i], i);
@@ -1354,13 +1428,13 @@ TEST_F(hmm2, snapshot)
/* Page 5 will be migrated to device 0. */
buffer->ptr = p + 5 * self->page_size;
- ret = hmm_dmirror_cmd(self->fd0, HMM_DMIRROR_MIGRATE, buffer, 1);
+ ret = hmm_migrate_sys_to_dev(self->fd0, buffer, 1);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, 1);
/* Page 6 will be migrated to device 1. */
buffer->ptr = p + 6 * self->page_size;
- ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, 1);
+ ret = hmm_migrate_sys_to_dev(self->fd1, buffer, 1);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, 1);
@@ -1377,9 +1451,16 @@ TEST_F(hmm2, snapshot)
ASSERT_EQ(m[2], HMM_DMIRROR_PROT_ZERO | HMM_DMIRROR_PROT_READ);
ASSERT_EQ(m[3], HMM_DMIRROR_PROT_READ);
ASSERT_EQ(m[4], HMM_DMIRROR_PROT_WRITE);
- ASSERT_EQ(m[5], HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL |
- HMM_DMIRROR_PROT_WRITE);
- ASSERT_EQ(m[6], HMM_DMIRROR_PROT_NONE);
+ if (!hmm_is_coherent_type(variant->device_number0)) {
+ ASSERT_EQ(m[5], HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL |
+ HMM_DMIRROR_PROT_WRITE);
+ ASSERT_EQ(m[6], HMM_DMIRROR_PROT_NONE);
+ } else {
+ ASSERT_EQ(m[5], HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL |
+ HMM_DMIRROR_PROT_WRITE);
+ ASSERT_EQ(m[6], HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE |
+ HMM_DMIRROR_PROT_WRITE);
+ }
hmm_buffer_free(buffer);
}
--
2.32.0
Technically I think this patch should be earlier in the series. As I
understand it patch 1 allows DEVICE_COHERENT pages to be inserted in the
page tables and therefore makes it possible for page table walkers to
see non-LRU pages.
Some more comments below:
Alex Sierra <[email protected]> writes:
> 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.
>
> We also introduced a FOLL_LRU flag that adds the same behaviour to
> follow_page and related APIs, to allow callers to specify that they
> expect to put pages on an LRU list.
This means by default GUP can return non-LRU pages. I didn't see
anywhere that would be a problem but I didn't check everything. Did you
check this or is there some other reason I've missed that makes this not
a problem?
[...]
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index a4e5eaf3eb01..eb3cfd679800 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -627,7 +627,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
> goto out;
> }
> page = vm_normal_page(vma, address, pteval);
> - if (unlikely(!page)) {
> + if (unlikely(!page) || unlikely(is_zone_device_page(page))) {
> result = SCAN_PAGE_NULL;
> goto out;
> }
> @@ -1276,7 +1276,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
> writable = true;
>
> page = vm_normal_page(vma, _address, pteval);
> - if (unlikely(!page)) {
> + if (unlikely(!page) || unlikely(is_zone_device_page(page))) {
> result = SCAN_PAGE_NULL;
> goto out_unmap;
> }
> @@ -1484,7 +1484,8 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr)
> goto abort;
>
> page = vm_normal_page(vma, addr, *pte);
> -
> + if (page && is_zone_device_page(page))
> + page = NULL;
> /*
> * Note that uprobe, debugger, or MAP_PRIVATE may change the
> * page table, but the new page will not be a subpage of hpage.
> @@ -1502,6 +1503,8 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr)
> if (pte_none(*pte))
> continue;
> page = vm_normal_page(vma, addr, *pte);
> + if (page && is_zone_device_page(page))
> + goto abort;
Are either of these two cases actually possible? DEVICE_COHERENT doesn't
currently support THP, so if I'm understanding correctly we couldn't
have a pte mapped DEVICE_COHERENT THP right? Assuming that's the case I
think WARN_ON_ONCE() would be better.
Otherwise I think everything else looks reasonable.
> page_remove_rmap(page, vma, false);
> }
>
> diff --git a/mm/ksm.c b/mm/ksm.c
> index 063a48eeb5ee..f16056efca21 100644
> --- a/mm/ksm.c
> +++ b/mm/ksm.c
> @@ -474,7 +474,7 @@ static int break_ksm(struct vm_area_struct *vma, unsigned long addr)
> do {
> cond_resched();
> page = follow_page(vma, addr,
> - FOLL_GET | FOLL_MIGRATION | FOLL_REMOTE);
> + FOLL_GET | FOLL_MIGRATION | FOLL_REMOTE | FOLL_LRU);
> if (IS_ERR_OR_NULL(page))
> break;
> if (PageKsm(page))
> @@ -559,7 +559,7 @@ static struct page *get_mergeable_page(struct rmap_item *rmap_item)
> if (!vma)
> goto out;
>
> - page = follow_page(vma, addr, FOLL_GET);
> + page = follow_page(vma, addr, FOLL_GET | FOLL_LRU);
> if (IS_ERR_OR_NULL(page))
> goto out;
> if (PageAnon(page)) {
> @@ -2288,7 +2288,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
> while (ksm_scan.address < vma->vm_end) {
> if (ksm_test_exit(mm))
> break;
> - *page = follow_page(vma, ksm_scan.address, FOLL_GET);
> + *page = follow_page(vma, ksm_scan.address, FOLL_GET | FOLL_LRU);
> if (IS_ERR_OR_NULL(*page)) {
> ksm_scan.address += PAGE_SIZE;
> cond_resched();
> diff --git a/mm/madvise.c b/mm/madvise.c
> index 1873616a37d2..e9c24c834e98 100644
> --- a/mm/madvise.c
> +++ b/mm/madvise.c
> @@ -413,7 +413,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd,
> continue;
>
> page = vm_normal_page(vma, addr, ptent);
> - if (!page)
> + if (!page || is_zone_device_page(page))
> continue;
>
> /*
> @@ -628,7 +628,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr,
> }
>
> page = vm_normal_page(vma, addr, ptent);
> - if (!page)
> + if (!page || is_zone_device_page(page))
> continue;
>
> /*
> diff --git a/mm/memory.c b/mm/memory.c
> index 76e3af9639d9..571a26805ee1 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -621,6 +621,13 @@ 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
> + * 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);
> @@ -4422,7 +4429,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
> pte = pte_modify(old_pte, vma->vm_page_prot);
>
> page = vm_normal_page(vma, vmf->address, pte);
> - if (!page)
> + if (!page || is_zone_device_page(page))
> goto out_map;
>
> /* TODO: handle PTE-mapped THP */
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 8c74107a2b15..e32edbecb0cd 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -528,7 +528,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
> if (!pte_present(*pte))
> continue;
> page = vm_normal_page(vma, addr, *pte);
> - if (!page)
> + if (!page || is_zone_device_page(page))
> continue;
> /*
> * vm_normal_page() filters out zero pages, but there might
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 6c31ee1e1c9b..c5d50e96ecd7 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1611,7 +1611,7 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
> goto out;
>
> /* FOLL_DUMP to ignore special (like zero) pages */
> - page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP);
> + page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP | FOLL_LRU);
>
> err = PTR_ERR(page);
> if (IS_ERR(page))
> @@ -1802,7 +1802,7 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
> goto set_status;
>
> /* FOLL_DUMP to ignore special (like zero) pages */
> - page = follow_page(vma, addr, FOLL_DUMP);
> + page = follow_page(vma, addr, FOLL_DUMP | FOLL_LRU);
>
> err = PTR_ERR(page);
> if (IS_ERR(page))
> diff --git a/mm/mlock.c b/mm/mlock.c
> index 716caf851043..b14e929084cc 100644
> --- a/mm/mlock.c
> +++ b/mm/mlock.c
> @@ -333,7 +333,7 @@ static int mlock_pte_range(pmd_t *pmd, unsigned long addr,
> if (!pte_present(*pte))
> continue;
> page = vm_normal_page(vma, addr, *pte);
> - if (!page)
> + if (!page || is_zone_device_page(page))
> continue;
> if (PageTransCompound(page))
> continue;
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index b69ce7a7b2b7..a6f3587ea29a 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -91,7 +91,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
> continue;
>
> page = vm_normal_page(vma, addr, oldpte);
> - if (!page || PageKsm(page))
> + if (!page || is_zone_device_page(page) || PageKsm(page))
> continue;
>
> /* Also skip shared copy-on-write pages */
On 5/23/2022 7:02 AM, Alistair Popple wrote:
> Technically I think this patch should be earlier in the series. As I
> understand it patch 1 allows DEVICE_COHERENT pages to be inserted in the
> page tables and therefore makes it possible for page table walkers to
> see non-LRU pages.
Patch will reordered in V3.
Regards,
Alex Sierra
>
> Some more comments below:
>
> Alex Sierra <[email protected]> writes:
>
>> 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.
>>
>> We also introduced a FOLL_LRU flag that adds the same behaviour to
>> follow_page and related APIs, to allow callers to specify that they
>> expect to put pages on an LRU list.
> This means by default GUP can return non-LRU pages. I didn't see
> anywhere that would be a problem but I didn't check everything. Did you
> check this or is there some other reason I've missed that makes this not
> a problem?
I have double checked all gup and pin_user_pages callers and none of
them seem to have interaction with LRU APIs.
Regards,
Alex Sierra
>
> [...]
>
>> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
>> index a4e5eaf3eb01..eb3cfd679800 100644
>> --- a/mm/khugepaged.c
>> +++ b/mm/khugepaged.c
>> @@ -627,7 +627,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
>> goto out;
>> }
>> page = vm_normal_page(vma, address, pteval);
>> - if (unlikely(!page)) {
>> + if (unlikely(!page) || unlikely(is_zone_device_page(page))) {
>> result = SCAN_PAGE_NULL;
>> goto out;
>> }
>> @@ -1276,7 +1276,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
>> writable = true;
>>
>> page = vm_normal_page(vma, _address, pteval);
>> - if (unlikely(!page)) {
>> + if (unlikely(!page) || unlikely(is_zone_device_page(page))) {
>> result = SCAN_PAGE_NULL;
>> goto out_unmap;
>> }
>> @@ -1484,7 +1484,8 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr)
>> goto abort;
>>
>> page = vm_normal_page(vma, addr, *pte);
>> -
>> + if (page && is_zone_device_page(page))
>> + page = NULL;
>> /*
>> * Note that uprobe, debugger, or MAP_PRIVATE may change the
>> * page table, but the new page will not be a subpage of hpage.
>> @@ -1502,6 +1503,8 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr)
>> if (pte_none(*pte))
>> continue;
>> page = vm_normal_page(vma, addr, *pte);
>> + if (page && is_zone_device_page(page))
>> + goto abort;
> Are either of these two cases actually possible? DEVICE_COHERENT doesn't
> currently support THP, so if I'm understanding correctly we couldn't
> have a pte mapped DEVICE_COHERENT THP right? Assuming that's the case I
> think WARN_ON_ONCE() would be better.
Correct, change included in V3 patch series.
Regards,
Alex
>
> Otherwise I think everything else looks reasonable.
>
>> page_remove_rmap(page, vma, false);
>> }
>>
>> diff --git a/mm/ksm.c b/mm/ksm.c
>> index 063a48eeb5ee..f16056efca21 100644
>> --- a/mm/ksm.c
>> +++ b/mm/ksm.c
>> @@ -474,7 +474,7 @@ static int break_ksm(struct vm_area_struct *vma, unsigned long addr)
>> do {
>> cond_resched();
>> page = follow_page(vma, addr,
>> - FOLL_GET | FOLL_MIGRATION | FOLL_REMOTE);
>> + FOLL_GET | FOLL_MIGRATION | FOLL_REMOTE | FOLL_LRU);
>> if (IS_ERR_OR_NULL(page))
>> break;
>> if (PageKsm(page))
>> @@ -559,7 +559,7 @@ static struct page *get_mergeable_page(struct rmap_item *rmap_item)
>> if (!vma)
>> goto out;
>>
>> - page = follow_page(vma, addr, FOLL_GET);
>> + page = follow_page(vma, addr, FOLL_GET | FOLL_LRU);
>> if (IS_ERR_OR_NULL(page))
>> goto out;
>> if (PageAnon(page)) {
>> @@ -2288,7 +2288,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
>> while (ksm_scan.address < vma->vm_end) {
>> if (ksm_test_exit(mm))
>> break;
>> - *page = follow_page(vma, ksm_scan.address, FOLL_GET);
>> + *page = follow_page(vma, ksm_scan.address, FOLL_GET | FOLL_LRU);
>> if (IS_ERR_OR_NULL(*page)) {
>> ksm_scan.address += PAGE_SIZE;
>> cond_resched();
>> diff --git a/mm/madvise.c b/mm/madvise.c
>> index 1873616a37d2..e9c24c834e98 100644
>> --- a/mm/madvise.c
>> +++ b/mm/madvise.c
>> @@ -413,7 +413,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd,
>> continue;
>>
>> page = vm_normal_page(vma, addr, ptent);
>> - if (!page)
>> + if (!page || is_zone_device_page(page))
>> continue;
>>
>> /*
>> @@ -628,7 +628,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr,
>> }
>>
>> page = vm_normal_page(vma, addr, ptent);
>> - if (!page)
>> + if (!page || is_zone_device_page(page))
>> continue;
>>
>> /*
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 76e3af9639d9..571a26805ee1 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -621,6 +621,13 @@ 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
>> + * 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);
>> @@ -4422,7 +4429,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
>> pte = pte_modify(old_pte, vma->vm_page_prot);
>>
>> page = vm_normal_page(vma, vmf->address, pte);
>> - if (!page)
>> + if (!page || is_zone_device_page(page))
>> goto out_map;
>>
>> /* TODO: handle PTE-mapped THP */
>> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
>> index 8c74107a2b15..e32edbecb0cd 100644
>> --- a/mm/mempolicy.c
>> +++ b/mm/mempolicy.c
>> @@ -528,7 +528,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
>> if (!pte_present(*pte))
>> continue;
>> page = vm_normal_page(vma, addr, *pte);
>> - if (!page)
>> + if (!page || is_zone_device_page(page))
>> continue;
>> /*
>> * vm_normal_page() filters out zero pages, but there might
>> diff --git a/mm/migrate.c b/mm/migrate.c
>> index 6c31ee1e1c9b..c5d50e96ecd7 100644
>> --- a/mm/migrate.c
>> +++ b/mm/migrate.c
>> @@ -1611,7 +1611,7 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,
>> goto out;
>>
>> /* FOLL_DUMP to ignore special (like zero) pages */
>> - page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP);
>> + page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP | FOLL_LRU);
>>
>> err = PTR_ERR(page);
>> if (IS_ERR(page))
>> @@ -1802,7 +1802,7 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
>> goto set_status;
>>
>> /* FOLL_DUMP to ignore special (like zero) pages */
>> - page = follow_page(vma, addr, FOLL_DUMP);
>> + page = follow_page(vma, addr, FOLL_DUMP | FOLL_LRU);
>>
>> err = PTR_ERR(page);
>> if (IS_ERR(page))
>> diff --git a/mm/mlock.c b/mm/mlock.c
>> index 716caf851043..b14e929084cc 100644
>> --- a/mm/mlock.c
>> +++ b/mm/mlock.c
>> @@ -333,7 +333,7 @@ static int mlock_pte_range(pmd_t *pmd, unsigned long addr,
>> if (!pte_present(*pte))
>> continue;
>> page = vm_normal_page(vma, addr, *pte);
>> - if (!page)
>> + if (!page || is_zone_device_page(page))
>> continue;
>> if (PageTransCompound(page))
>> continue;
>> diff --git a/mm/mprotect.c b/mm/mprotect.c
>> index b69ce7a7b2b7..a6f3587ea29a 100644
>> --- a/mm/mprotect.c
>> +++ b/mm/mprotect.c
>> @@ -91,7 +91,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
>> continue;
>>
>> page = vm_normal_page(vma, addr, oldpte);
>> - if (!page || PageKsm(page))
>> + if (!page || is_zone_device_page(page) || PageKsm(page))
>> continue;
>>
>> /* Also skip shared copy-on-write pages */