kernel/tools/testing/selftests/vm/ksm_tests.c, branch linux-6.2.y

selftests/vm: add test to measure MADV_UNMERGEABLE performance

2022-12-12T02:12:08Z

Let's add a test to measure performance of KSM breaking not triggered via COW, but triggered by disabling KSM on an area filled with KSM pages via MADV_UNMERGEABLE. Link: https://lkml.kernel.org/r/20221021101141.84170-2-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Peter Xu Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: John Hubbard Cc: Matthew Wilcox (Oracle) Cc: Shuah Khan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

selftests/vm: use top_srcdir instead of recomputing relative paths

2022-10-05T17:05:17Z

In various places both in t/t/s/v/Makefile as well as some of the test sources, we were referring to headers or directories using some fairly long relative paths. Since we have a working top_srcdir variable though, which refers to the root of the kernel tree, we can clean up all of these "up and over" relative paths, just relying on the single variable instead. Signed-off-by: Axel Rasmussen Signed-off-by: Shuah Khan

selftests: vm: Fix resource leak when return error

2022-06-16T20:14:08Z

When return on an error path, file handle need to be closed to prevent resource leak Signed-off-by: Ding Xiang Reviewed-by: Shuah Khan Signed-off-by: Shuah Khan

selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests

2022-05-25T17:47:49Z

Patch series "selftests: vm: a few fixup patches". This series contains three fixup patches for vm selftests. They are independent. Please see the patches. This patch (of 3): Currently, ksm_tests operates "merge_across_nodes" with NUMA either enabled or disabled. In a system with NUMA disabled, these operations will fail and output a misleading report given "merge_across_nodes" does not exist in sysfs: ---------------------------- running ./ksm_tests -M -p 10 ---------------------------- f /sys/kernel/mm/ksm/merge_across_nodes fopen: No such file or directory Cannot save default tunables [FAIL] ---------------------- So check numa_available() before those operations to skip them if NUMA is disabled. Link: https://lkml.kernel.org/r/20220521083825.319654-1-patrick.wang.shcn@gmail.com Link: https://lkml.kernel.org/r/20220521083825.319654-2-patrick.wang.shcn@gmail.com Signed-off-by: Patrick Wang Cc: Shuah Khan Signed-off-by: Andrew Morton

selftest/vm: add util.h and and move helper functions there

2022-03-25T02:06:45Z

Avoid code duplication by adding util.h. No functional change in this patch. Link: https://lkml.kernel.org/r/20220307054355.149820-1-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V Cc: Shuah Khan Cc: Mike Rapoport Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

selftests: vm: add KSM huge pages merging time test

2021-11-06T20:30:41Z

Add test case of KSM merging time using mostly huge pages Link: https://lkml.kernel.org/r/20211013044045.360251-1-pedrodemargomes@gmail.com Signed-off-by: Pedro Demarchi Gomes Cc: Zhansaya Bagdauletkyzy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

selftest/vm: fix ksm selftest to run with different NUMA topologies

2021-11-06T20:30:41Z

Platforms can have non-contiguous NUMA nodes like below #numactl -H available: 2 nodes (0,8) ..... node distances: node 0 8 0: 10 40 8: 40 10 #numactl -H available: 1 nodes (1) .... node distances: node 1 1: 10 Hence update the test to not assume the presence of Node 0 and 1 and also use numa_num_configured_nodes() instead of numa_max_node for finding whether to skip the test. Link: https://lkml.kernel.org/r/20210914141414.350759-1-aneesh.kumar@linux.ibm.com Fixes: 82e717ad3501 ("selftests: vm: add KSM merging across nodes test") Signed-off-by: Aneesh Kumar K.V Reviewed-by: Pasha Tatashin Cc: Zhansaya Bagdauletkyzy Cc: Pavel Tatashin Cc: Tyler Hicks Cc: Hugh Dickins Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

selftests: vm: add COW time test for KSM pages

2021-09-03T16:58:18Z

Since merged pages are copied every time they need to be modified, the write access time is different between shared and non-shared pages. Add ksm_cow_time() function which evaluates latency of these COW breaks. First, 4000 pages are allocated and the time, required to modify 1 byte in every other page, is measured. After this, the pages are merged into 2000 pairs and in each pair, 1 page is modified (i.e. they are decoupled) to detect COW breaks. The time needed to break COW of merged pages is then compared with performance of non-shared pages. The test is run as follows: ./ksm_tests -C The output: Total size: 15 MiB Not merged pages: Total time: 0.002185489 s Average speed: 3202.945 MiB/s Merged pages: Total time: 0.004386872 s Average speed: 1595.670 MiB/s Link: https://lkml.kernel.org/r/1d03ee0d1b341959d4b61672c6401d498bff5652.1629386192.git.zhansayabagdaulet@gmail.com Signed-off-by: Zhansaya Bagdauletkyzy Reviewed-by: Tyler Hicks Reviewed-by: Pavel Tatashin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

selftests: vm: add KSM merging time test

2021-09-03T16:58:18Z

Patch series "add KSM performance tests", v3. Extend KSM self tests with a performance benchmark. These tests are not part of regular regression testing, as they are mainly intended to be used by developers making changes to the memory management subsystem. This patch (of 2): Add ksm_merge_time() function to determine speed and time needed for merging. The total spent time is shown in seconds while speed is in MiB/s. User must specify the size of duplicated memory area (in MiB) before running the test. The test is run as follows: ./ksm_tests -P -s 100 The output: Total size: 100 MiB Total time: 0.201106786 s Average speed: 497.248 MiB/s Link: https://lkml.kernel.org/r/cover.1629386192.git.zhansayabagdaulet@gmail.com Link: https://lkml.kernel.org/r/318b946ac80cc9205c89d0962048378f7ce0705b.1629386192.git.zhansayabagdaulet@gmail.com Signed-off-by: Zhansaya Bagdauletkyzy Reviewed-by: Tyler Hicks Reviewed-by: Pavel Tatashin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

selftests: vm: add KSM merging across nodes test

2021-09-03T16:58:18Z

Add check_ksm_numa_merge() function to test that pages in different NUMA nodes are being handled properly. First, two duplicate pages are allocated in two separate NUMA nodes using the libnuma library. Since there is one unique page in each node, with merge_across_nodes = 0, there won't be any shared pages. If merge_across_nodes is set to 1, the pages will be treated as usual duplicate pages and will be merged. If NUMA config is not enabled or the number of NUMA nodes is less than two, then the test is skipped. The test is run as follows: ./ksm_tests -N Link: https://lkml.kernel.org/r/071c17b5b04ebb0dfeba137acc495e5dd9d2a719.1626252248.git.zhansayabagdaulet@gmail.com Signed-off-by: Zhansaya Bagdauletkyzy Reviewed-by: Pavel Tatashin Reviewed-by: Tyler Hicks Cc: Hugh Dickins Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds