kernel/linux.git/tools/testing/selftests/vm/compaction_test.c, branch v6.1.168

selftests/mm: compaction_test: support platform with huge mount of memory

2025-05-22T12:10:08+00:00

commit ab00ddd802f80e31fc9639c652d736fe3913feae upstream. When running mm selftest to verify mm patches, 'compaction_test' case failed on an x86 server with 1TB memory. And the root cause is that it has too much free memory than what the test supports. The test case tries to allocate 100000 huge pages, which is about 200 GB for that x86 server, and when it succeeds, it expects it's large than 1/3 of 80% of the free memory in system. This logic only works for platform with 750 GB ( 200 / (1/3) / 80% ) or less free memory, and may raise false alarm for others. Fix it by changing the fixed page number to self-adjustable number according to the real number of free memory. Link: https://lkml.kernel.org/r/20250423103645.2758-1-feng.tang@linux.alibaba.com Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory") Signed-off-by: Feng Tang Acked-by: Dev Jain Reviewed-by: Baolin Wang Tested-by: Baolin Wang Cc: Shuah Khan Cc: Sri Jayaramappa Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

selftests/mm: compaction_test: fix bogus test success on Aarch64

2024-06-21T12:35:41+00:00

[ Upstream commit d4202e66a4b1fe6968f17f9f09bbc30d08f028a1 ] Patch series "Fixes for compaction_test", v2. The compaction_test memory selftest introduces fragmentation in memory and then tries to allocate as many hugepages as possible. This series addresses some problems. On Aarch64, if nr_hugepages == 0, then the test trivially succeeds since compaction_index becomes 0, which is less than 3, due to no division by zero exception being raised. We fix that by checking for division by zero. Secondly, correctly set the number of hugepages to zero before trying to set a large number of them. Now, consider a situation in which, at the start of the test, a non-zero number of hugepages have been already set (while running the entire selftests/mm suite, or manually by the admin). The test operates on 80% of memory to avoid OOM-killer invocation, and because some memory is already blocked by hugepages, it would increase the chance of OOM-killing. Also, since mem_free used in check_compaction() is the value before we set nr_hugepages to zero, the chance that the compaction_index will be small is very high if the preset nr_hugepages was high, leading to a bogus test success. This patch (of 3): Currently, if at runtime we are not able to allocate a huge page, the test will trivially pass on Aarch64 due to no exception being raised on division by zero while computing compaction_index. Fix that by checking for nr_hugepages == 0. Anyways, in general, avoid a division by zero by exiting the program beforehand. While at it, fix a typo, and handle the case where the number of hugepages may overflow an integer. Link: https://lkml.kernel.org/r/20240521074358.675031-1-dev.jain@arm.com Link: https://lkml.kernel.org/r/20240521074358.675031-2-dev.jain@arm.com Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory") Signed-off-by: Dev Jain Cc: Anshuman Khandual Cc: Shuah Khan Cc: Sri Jayaramappa Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

selftests/mm: log a consistent test name for check_compaction

2024-06-21T12:35:41+00:00

[ Upstream commit f3b7568c49420d2dcd251032c9ca1e069ec8a6c9 ] Every test result report in the compaction test prints a distinct log messae, and some of the reports print a name that varies at runtime. This causes problems for automation since a lot of automation software uses the printed string as the name of the test, if the name varies from run to run and from pass to fail then the automation software can't identify that a test changed result or that the same tests are being run. Refactor the logging to use a consistent name when printing the result of the test, printing the existing messages as diagnostic information instead so they are still available for people trying to interpret the results. Link: https://lkml.kernel.org/r/20240209-kselftest-mm-cleanup-v1-2-a3c0386496b5@kernel.org Signed-off-by: Mark Brown Cc: Muhammad Usama Anjum Cc: Ryan Roberts Cc: Shuah Khan Signed-off-by: Andrew Morton Stable-dep-of: d4202e66a4b1 ("selftests/mm: compaction_test: fix bogus test success on Aarch64") Signed-off-by: Sasha Levin

selftests/mm: conform test to TAP format output

2024-06-21T12:35:41+00:00

[ Upstream commit 9a21701edc41465de56f97914741bfb7bfc2517d ] Conform the layout, informational and status messages to TAP. No functional change is intended other than the layout of output messages. Link: https://lkml.kernel.org/r/20240101083614.1076768-1-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum Cc: Shuah Khan Signed-off-by: Andrew Morton Stable-dep-of: d4202e66a4b1 ("selftests/mm: compaction_test: fix bogus test success on Aarch64") Signed-off-by: Sasha Levin

selftests/mm: compaction_test: fix incorrect write of zero to nr_hugepages

2024-06-21T12:35:41+00:00

[ Upstream commit 9ad665ef55eaad1ead1406a58a34f615a7c18b5e ] Currently, the test tries to set nr_hugepages to zero, but that is not actually done because the file offset is not reset after read(). Fix that using lseek(). Link: https://lkml.kernel.org/r/20240521074358.675031-3-dev.jain@arm.com Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory") Signed-off-by: Dev Jain Cc: Cc: Anshuman Khandual Cc: Shuah Khan Cc: Sri Jayaramappa Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

selftests/vm: 8x compaction_test speedup

2020-10-14T01:38:34+00:00

This patch reduces the running time for compaction_test from about 27 sec, to 3.3 sec, which is about an 8x speedup. These numbers are for an Intel x86_64 system with 32 GB of DRAM. The compaction_test.c program was spending most of its time doing mmap(), 1 MB at a time, on about 25 GB of memory. Instead, do the mmaps 100 MB at a time. (Going past 100 MB doesn't make things go much faster, because other parts of the program are using the remaining time.) Signed-off-by: John Hubbard Signed-off-by: Andrew Morton Acked-by: Sri Jayaramappa Cc: Shuah Khan Cc: Mel Gorman Link: https://lkml.kernel.org/r/20201002080621.551044-2-jhubbard@nvidia.com Signed-off-by: Linus Torvalds

selftests: vm: return Kselftest Skip code for skipped tests

2018-06-18T15:11:10+00:00

When vm test is skipped because of unmet dependencies and/or unsupported configuration, it exits with error which is treated as a fail by the Kselftest framework. This leads to false negative result even when the test could not be run. Change it to return kselftest skip code when a test gets skipped to clearly report that the test could not be run. Kselftest framework SKIP code is 4 and the framework prints appropriate messages to indicate that the test is skipped. Signed-off-by: Shuah Khan (Samsung OSG) Acked-by: Mike Rapoport Signed-off-by: Shuah Khan (Samsung OSG)

kselftest: fix OOM in memory compaction test

2018-01-10T15:22:47+00:00

Running the compaction_test sometimes results in out-of-memory failures. When I debugged this, it turned out that the code to reset the number of hugepages to the initial value is simply broken since we write into an open sysctl file descriptor multiple times without seeking back to the start. Adding the lseek here fixes the problem. Cc: stable@vger.kernel.org Reported-by: Naresh Kamboju Link: https://bugs.linaro.org/show_bug.cgi?id=3145 Signed-off-by: Arnd Bergmann Signed-off-by: Shuah Khan

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

selftests/vm: write strlen length instead of sizeof to nr_hugepages

2016-06-27T19:18:26+00:00

When setting back the initial value to nr_hugepages, the test was writing a length sizeof of the string and checking that strlen was writen. Since those values are not the same, use strlen in both place instead. Also make the error messages more explicit to help in future debugging. Signed-off-by: Yannick Brosseau Signed-off-by: Shuah Khan