On 9/21/26 6:35 PM, Yeoreum Yun wrote:
Although the child process in collapse_fork*() or collapse_max_ptes_shared() reports `KSFT_FAIL`, the result is ignored because the test only checks whether the parent’s page was collapsed into a huge page. As a result, the test is considered successful whenever the parent’s page is a huge page, even if the child test fails, as shown below: # # Run test: collapse_max_ptes_shared (khugepaged:anon) # Allocate huge page... OK # Share huge page over fork()... OK # Trigger CoW on page 1023 of 2048... OK # Maybe collapse with max_ptes_shared exceeded.... OK # Trigger CoW on page 1024 of 2048... Fail Bail out! Unexpected huge page # Planned tests != run tests (26 != 23) # Totals: pass:23 fail:0 xfail:0 xpass:0 skip:0 error:0 // child failed. # Check if parent still has huge page... OK // parent hpage success ok 24 collapse_max_ptes_shared // considered as success ... # Totals: pass:26 fail:0 xfail:0 xpass:0 skip:0 error:0 To address this, propagate the child’s failure and skip the subsequent check in the parent. Signed-off-by: Yeoreum Yun <[email protected]> ---
Make sense to me. Reviewed-by: Baolin Wang <[email protected]>

