kernel/tools/testing/selftests/vm/ksm_functional_tests.c, branch linux-6.2.yHosts the 0x221E linux distro kernel.https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-6.2.y2022-12-12T02:12:21Zselftests/vm: ksm_functional_tests: fixes for 32bit2022-12-12T02:12:21ZDavid Hildenbranddavid@redhat.com2022-12-05T19:37:16Zurn:sha1:9d789c3b4170574baa4242dd8cae5988cf97d48d
The test currently fails on 32bit. Fixing the "-1ull" vs. "-1ul" seems
to make the test pass and the compiler happy.
Note: This test is not in mm-stable yet. This fix should be squashed into
"selftests/vm: add KSM unmerge tests".
Link: https://lkml.kernel.org/r/20221205193716.276024-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
selftests/vm: add KSM unmerge tests2022-12-12T02:12:07ZDavid Hildenbranddavid@redhat.com2022-10-21T10:11:36Zurn:sha1:93fb70aa5904c2577fab8100fa990ecfa4f5b4c7
Patch series "mm/ksm: break_ksm() cleanups and fixes", v2.
This series cleans up and fixes break_ksm(). In summary, we no longer use
fake write faults to break COW but instead FAULT_FLAG_UNSHARE. Further,
we move away from using follow_page() --- that we can hopefully remove
completely at one point --- and use new walk_page_range_vma() instead.
Fortunately, we can get rid of VM_FAULT_WRITE and FOLL_MIGRATION in common
code now.
Extend the existing ksm tests by an unmerge benchmark, and a some new
unmerge tests.
Also, add a selftest to measure MADV_UNMERGEABLE performance. In my setup
(AMD Ryzen 9 3900X), running the KSM selftest to test unmerge performance
on 2 GiB (taskset 0x8 ./ksm_tests -D -s 2048), this results in a
performance degradation of ~6% -- 7% (old: ~5250 MiB/s, new: ~4900 MiB/s).
I don't think we particularly care for now, but it's good to be aware of
the implication.
This patch (of 9):
Let's add three unmerge tests (MADV_UNMERGEABLE unmerging all pages in the
range).
test_unmerge(): basic unmerge tests
test_unmerge_discarded(): have some pte_none() entries in the range
test_unmerge_uffd_wp(): protect the merged pages using uffd-wp
ksm_tests.c currently contains a mixture of benchmarks and tests, whereby
each test is carried out by executing the ksm_tests binary with specific
parameters. Let's add new ksm_functional_tests.c that performs multiple,
smaller functional tests all at once.
Link: https://lkml.kernel.org/r/20221021101141.84170-1-david@redhat.com
Link: https://lkml.kernel.org/r/20221021101141.84170-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>