# Copyright 2022 syzkaller project authors. All rights reserved. # Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file. config: - CMDLINE: [append, "smp.csd_lock_timeout=100000 watchdog_thresh=55 workqueue.watchdog_thresh=140 sysctl.net.core.netdev_unregister_timeout_secs=140 dummy_hcd.num=32 max_loop=32 nbds_max=32"] # Deterministic hang/stall detection. # Without careful tuning the same hang/stall can be detected in multiple, radically-different ways. # For example, an infinite loop can be detected as CPU stall, RCU stall, hung task or workqueue stall. # This may lead to lots of duplicate bugs. In order to prevent this we strictly order hang/stall detection # timeouts based on their causality (CPU stall can cause hung task, but not vise versa). See #516 for details. # # 1. RCU stalls has the highest priority. # RCU_CPU_STALL_TIMEOUT=100 results in stalls detected after 100-101 secs. # This also includes CSD lock timeout (CONFIG_CSD_LOCK_WAIT_DEBUG + smp.csd_lock_timeout=100000(ms)). # # 2. Then softlockup detector. # kernel.watchdog_thresh = 55 detects stalls after 110-132 secs. # # 3. Then hung tasks, workqueue stalls and netdev unregister hangs. # Unfortunately we can't separate them because that would require setting "no output" timeout to 10+ minutes. # watchdog_thresh=140 and DEFAULT_HUNG_TASK_TIMEOUT=140 both result in detection after 140-280 secs. # # 4. Finally, "no output" crashes. # sys/targets.Timeouts.NoOutput is set to 300 secs. # # Don't change these values without considering all other values as well. # Note: executor also sets hung_task_check_interval_secs=20 sysctl. # Note: gVisor watchdog timeout is 3 mins + 1/4 of that for checking period = 3m45s. # Note: other arches that use qemu emulation scale all these timeouts by 3 (sys/targets.Timeouts.Scale). - RCU_CPU_STALL_TIMEOUT: 100 # The constraints repeat constraints on inclusion of debug.yml which enables hung task detection. - DEFAULT_HUNG_TASK_TIMEOUT: [140, -nonoise, -kmsan, -kcsan, -kmemleak] # A zero RCU_EXP_CPU_STALL_TIMEOUT value makes it equal to RCU_CPU_STALL_TIMEOUT. - RCU_EXP_CPU_STALL_TIMEOUT: [0, v5.19]