There are several watchdogs, using different timeout values, so we need to set printk offloading threshold appropriately. This patch set extends offloading_threshold() to take RCU, softlockup and hardlockup timeouts into consideration.
Signed-off-by: Sergey Senozhatsky <[email protected]> --- kernel/printk/printk.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index f4e84f83bff5..3d4df3f02854 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -492,10 +492,29 @@ void printk_emergency_end(void) } EXPORT_SYMBOL_GPL(printk_emergency_end); +/* + * Adjust max timeout value in the following order: + * a) 1/2 of RCU stall timeout - it is usually the largest + * b) 1/2 of hardlockup threshold (if enabled) - lower than softlockup + * c) 1/2 of softlockup threshold (if enabled) + * e) default value - 10 seconds + */ static inline int offloading_threshold(void) { + int timeout = CONFIG_RCU_CPU_STALL_TIMEOUT / 2 + 1; + +#ifdef CONFIG_LOCKUP_DETECTOR + /* Hardlockup detector has a sample_period of `watchdog_thresh'. */ + if ((watchdog_enabled & NMI_WATCHDOG_ENABLED) && watchdog_thresh) + return min(timeout, watchdog_thresh / 2) + 1; + + /* Softlockup uses '2 * watchdog_thresh' as a threshold value. */ + if ((watchdog_enabled & SOFT_WATCHDOG_ENABLED) && watchdog_thresh) + return min(timeout, watchdog_thresh) + 1; +#endif + /* Default threshold value is 10 seconds */ - return 10; + return min(10, timeout); } /* -- 2.15.1
