kernel/tools/testing/selftests/powerpc/dscr, branch linux-rolling-stable

selftests/powerpc: Give all tests 2 minutes timeout

2024-11-07T11:36:30Z

Each of the powerpc selftests runs with a timeout of 2 minutes by default (see tools/testing/selftests/powerpc/harness.c). But when tests are run with run_kselftest.sh it uses a timeout of 45 seconds, meaning some tests run OK standalone but fail when run with the test runner. So tell run_kselftest.sh to give each test 130 seconds, that should allow the tests to complete, or be killed by the powerpc test harness after 2 minutes. If for some reason the harness fails, or for the few tests that don't use the harness, the 130 second timeout should catch them if they get stuck. Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241106130453.1741013-2-mpe@ellerman.id.au

selftests/powerpc: make sub-folders buildable on their own

2024-04-29T13:54:42Z

Build breaks when executing make with run_tests for sub-folders under powerpc. This is because, CFLAGS and GIT_VERSION macros are defined in Makefile of toplevel powerpc folder. make: Entering directory '/home/maddy/linux/tools/testing/selftests/powerpc/mm' gcc hugetlb_vs_thp_test.c ../harness.c ../utils.c -o /home/maddy/selftest_output//hugetlb_vs_thp_test hugetlb_vs_thp_test.c:6:10: fatal error: utils.h: No such file or directory 6 | #include "utils.h" | ^~~~~~~~~ compilation terminated. Fix this by adding the flags.mk in each sub-folder Makefile. Also remove the CFLAGS and GIT_VERSION macros from powerpc/ folder Makefile since the same is definied in flags.mk Signed-off-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman Link: https://msgid.link/20240229093711.581230-3-maddy@linux.ibm.com

selftests/powerpc/dscr: Restore timeout to DSCR selftests

2023-04-20T03:21:46Z

Reducing the time taken by dscr_sysfs_test.c allows restoring the default timeout, which was removed in commit 850507f30c38 ("selftests/powerpc: Turn off timeout setting for benchmarks, dscr, signal, tm") because that test took too long. Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://msgid.link/20230406043320.125138-8-bgray@linux.ibm.com

selftests/powerpc/dscr: Speed up DSCR sysfs tests

2023-04-20T03:21:46Z

This test case is extremely slow, taking around a minute compared to most of the other DSCR tests taking a second at most. Perf shows most time is spent by the kernel switching to each CPU it reads in /sys/devices/system/cpu. This switching is an unavoidable consequnce of reading all the .../cpuN/dscr values. Remove the outer iteration loop from this test case, reducing the reads from 1600 to 16. This still updates the DSCR 16 times and verifies on every CPU each time, so I do not expect the lower coverage to be meaningful. The speedup is significant: back down to ~1 second like the other tests. Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://msgid.link/20230406043320.125138-7-bgray@linux.ibm.com

selftests/powerpc/dscr: Improve DSCR explicit random test case

2023-04-20T03:21:45Z

The tests currently have a single writer thread updating the system DSCR with a 1/1000 chance looped only 100 times. So only around one in 10 runs actually do anything. * Add multiple threads to the dscr_explicit_random_test case. * Use a barrier to make all the threads start work as simultaneously as possible. * Use a rwlock and make all threads have a reasonable chance to write to the DSCR on each iteration. PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP is used to prevent writers from starving while all the other threads keep reading. Logging the reads/writes shows a decent mix across the whole test. * Allow all threads a chance to write. * Make the chance of writing more likely. Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://msgid.link/20230406043320.125138-6-bgray@linux.ibm.com

selftests/powerpc/dscr: Add lockstep test cases to DSCR explicit tests

2023-04-20T03:21:45Z

Add new cases to the relevant tests that use explicitly synchronized threads to test the behaviour across context switches with less randomness. By locking the participants to the same CPU we guarantee a context switch occurs each time they make progress, which is a likely failure point if the kernel is not tracking the thread local DSCR correctly. The random case is left in to keep exercising potential edge cases. Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://msgid.link/20230406043320.125138-5-bgray@linux.ibm.com

selftests/powerpc/dscr: Correct typos

2023-04-20T03:21:45Z

Correct a couple of typos while working on other improvements to the DSCR tests. Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://msgid.link/20230406043320.125138-2-bgray@linux.ibm.com

selftests/powerpc: Add {read,write}_{long,ulong}

2023-02-09T12:56:45Z

Add helper functions to read and write (unsigned) long values directly from/to files. One of the kernel interfaces uses hex strings, so we need to allow passing a base too. Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20230203003947.38033-5-bgray@linux.ibm.com

selftests/powerpc: Add generic read/write file util

2023-02-09T12:56:45Z

File read/write is reimplemented in about 5 different ways in the various PowerPC selftests. This indicates it should be a common util. Add a common read_file / write_file implementation and convert users to it where (easily) possible. Signed-off-by: Benjamin Gray Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20230203003947.38033-2-bgray@linux.ibm.com

selftests/powerpc: Fix resource leaks

2022-12-05T10:39:15Z

In check_all_cpu_dscr_defaults, opendir() opens the directory stream. Add missing closedir() in the error path to release it. In check_cpu_dscr_default, open() creates an open file descriptor. Add missing close() in the error path to release it. Fixes: ebd5858c904b ("selftests/powerpc: Add test for all DSCR sysfs interfaces") Signed-off-by: Miaoqian Lin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20221205084429.570654-1-linmq006@gmail.com