On 7/26/22 14:03, John Hubbard wrote:
On 7/25/22 11:36, Ralph Campbell wrote:
Add a simple test case for when hmm_range_fault() is called with the
HMM_PFN_REQ_FAULT flag and a device private PTE is found for a device
other than the hmm_range::dev_private_owner. This should cause the
page to be faulted back to system memory from the other device and the
PFN returned in the output array.
Signed-off-by: Ralph Campbell <rcampbell@xxxxxxxxxx>
---
tools/testing/selftests/vm/hmm-tests.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/vm/hmm-tests.c
b/tools/testing/selftests/vm/hmm-tests.c
index 203323967b50..a5ce7cc2e7aa 100644
--- a/tools/testing/selftests/vm/hmm-tests.c
+++ b/tools/testing/selftests/vm/hmm-tests.c
@@ -1520,9 +1520,19 @@ TEST_F(hmm2, double_map)
for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
ASSERT_EQ(ptr[i], i);
- /* Punch a hole after the first page address. */
- ret = munmap(buffer->ptr + self->page_size, self->page_size);
If this removal was intentional, then it should be mentioned in the
commit log.
Yes. It does nothing, probably a copy & paste error.
I'll update the description and send a v3.
+ /* Migrate pages to device 1 and try to read from device 0. */
+ ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer,
npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ ret = hmm_dmirror_cmd(self->fd0, HMM_DMIRROR_READ, buffer, npages);
ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+ ASSERT_EQ(buffer->faults, 1);
+
+ /* Check what device 0 read. */
+ for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], i);
I'm assuming that your testing shows that this fails without patch 1,
and succeeds with patch 1 applied? Apologies for such an obvious
question... :)
Yes. Without the patch, the ASSERT_EQ(ret, 0) would trigger.
With the patch, ASSERT_EQ(buffer->faults, 1) verifies that the pages
were faulted in from device 1 when device 0 tries to read them.
