On Sat, Aug 16, 2025 at 09:31:09AM +0530, Aboorva Devarajan wrote: >From: Donet Tom <[email protected]> > >This patch fixed 2 issues. > >1) After fork() in test_prctl_fork, the child process uses the file >descriptors from the parent process to read ksm_stat and >ksm_merging_pages. This results in incorrect values being read (parent >process ksm_stat and ksm_merging_pages will be read in child), causing >the test to fail. > >This patch calls init_global_file_handles() in the child process to >ensure that the current process's file descriptors are used to read >ksm_stat and ksm_merging_pages. > >2) All tests currently call ksm_merge to trigger page merging. >To ensure the system remains in a consistent state for subsequent >tests, it is better to call ksm_unmerge during the test cleanup phase > >In the test_prctl_fork test, after a fork(), reading ksm_merging_pages >in the child process returns a non-zero value because a previous test >performed a merge, and the child's memory state is inherited from the >parent. > >Although the child process calls ksm_unmerge, the ksm_merging_pages >counter in the parent is reset to zero, while the child's counter >remains unchanged. This discrepancy causes the test to fail. > >To avoid this issue, each test should call ksm_unmerge during cleanup >to ensure the counter is reset and the system is in a clean state for >subsequent tests. > >execv argument is an array of pointers to null-terminated strings. >In this patch we also added NULL in the execv argument. > >Fixes: 6c47de3be3a0 ("selftest/mm: ksm_functional_tests: extend test case for >ksm fork/exec") >Co-developed-by: Aboorva Devarajan <[email protected]> >Signed-off-by: Aboorva Devarajan <[email protected]> >Signed-off-by: Donet Tom <[email protected]>
Reviewed-by: Wei Yang <[email protected]> -- Wei Yang Help you, Help me
