| Message ID | 20220725183615.4118795-3-rcampbell@nvidia.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/hmm: fault non-owner device private entries | expand |
Reviewed-by: Alistair Popple <apopple@nvidia.com> Ralph Campbell <rcampbell@nvidia.com> writes: > 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@nvidia.com> > --- > 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); > + /* 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); > > hmm_buffer_free(buffer); > }
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@nvidia.com> > --- > 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. > + /* 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... :) > > hmm_buffer_free(buffer); > } thanks,
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@nvidia.com> >> --- >> 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.
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); + /* 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); hmm_buffer_free(buffer); }
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@nvidia.com> --- tools/testing/selftests/vm/hmm-tests.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)