From: Hauke Mehrtens Date: Wed, 12 Feb 2020 10:49:02 +0000 (+0100) Subject: build: Add additional kernel debug options X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=b951f53fbae3b6ad298da3d123a48fa260493a91;p=oweals%2Fopenwrt.git build: Add additional kernel debug options Make it possible to activate some additional kernel debug options. This can be used to debug some problems in kernel drivers. Signed-off-by: Hauke Mehrtens Reviewed-by: Alexandru Ardelean --- diff --git a/config/Config-kernel.in b/config/Config-kernel.in index 5e677e6afd..52e74a175b 100644 --- a/config/Config-kernel.in +++ b/config/Config-kernel.in @@ -377,6 +377,74 @@ config KERNEL_PROVE_LOCKING select KERNEL_DEBUG_KERNEL default n +config KERNEL_LOCKUP_DETECTOR + bool "Compile the kernel with detect Hard and Soft Lockups" + depends on KERNEL_DEBUG_KERNEL + help + Say Y here to enable the kernel to act as a watchdog to detect + hard and soft lockups. + + Softlockups are bugs that cause the kernel to loop in kernel + mode for more than 20 seconds, without giving other tasks a + chance to run. The current stack trace is displayed upon + detection and the system will stay locked up. + + Hardlockups are bugs that cause the CPU to loop in kernel mode + for more than 10 seconds, without letting other interrupts have a + chance to run. The current stack trace is displayed upon detection + and the system will stay locked up. + + The overhead should be minimal. A periodic hrtimer runs to + generate interrupts and kick the watchdog task every 4 seconds. + An NMI is generated every 10 seconds or so to check for hardlockups. + + The frequency of hrtimer and NMI events and the soft and hard lockup + thresholds can be controlled through the sysctl watchdog_thresh. + +config KERNEL_DETECT_HUNG_TASK + bool "Compile the kernel with detect Hung Tasks" + depends on KERNEL_DEBUG_KERNEL + default KERNEL_LOCKUP_DETECTOR + help + Say Y here to enable the kernel to detect "hung tasks", + which are bugs that cause the task to be stuck in + uninterruptible "D" state indefinitely. + + When a hung task is detected, the kernel will print the + current stack trace (which you should report), but the + task will stay in uninterruptible state. If lockdep is + enabled then all held locks will also be reported. This + feature has negligible overhead. + +config KERNEL_WQ_WATCHDOG + bool "Compile the kernel with detect Workqueue Stalls" + depends on KERNEL_DEBUG_KERNEL + help + Say Y here to enable stall detection on workqueues. If a + worker pool doesn't make forward progress on a pending work + item for over a given amount of time, 30s by default, a + warning message is printed along with dump of workqueue + state. This can be configured through kernel parameter + "workqueue.watchdog_thresh" and its sysfs counterpart. + +config KERNEL_DEBUG_ATOMIC_SLEEP + bool "Compile the kernel with sleep inside atomic section checking" + depends on KERNEL_DEBUG_KERNEL + help + If you say Y here, various routines which may sleep will become very + noisy if they are called inside atomic sections: when a spinlock is + held, inside an rcu read side critical section, inside preempt disabled + sections, inside an interrupt, etc... + +config KERNEL_DEBUG_VM + bool "Compile the kernel with debug VM" + depends on KERNEL_DEBUG_KERNEL + help + Enable this to turn on extended checks in the virtual-memory system + that may impact performance. + + If unsure, say N. + config KERNEL_PRINTK_TIME bool "Enable printk timestamps" default y diff --git a/target/linux/generic/config-4.14 b/target/linux/generic/config-4.14 index 5a9b82db80..d1ce30d2f7 100644 --- a/target/linux/generic/config-4.14 +++ b/target/linux/generic/config-4.14 @@ -594,6 +594,7 @@ CONFIG_BLOCK=y # CONFIG_BONDING is not set # CONFIG_BOOKE_WDT is not set CONFIG_BOOKE_WDT_DEFAULT_TIMEOUT=3 +# CONFIG_BOOTPARAM_HUNG_TASK_PANIC is not set # CONFIG_BOOT_PRINTK_DELAY is not set CONFIG_BOOT_RAW=y CONFIG_BPF=y @@ -1073,6 +1074,9 @@ CONFIG_DEBUG_KERNEL=y # CONFIG_DEBUG_UART_BCM63XX is not set # CONFIG_DEBUG_VIRTUAL is not set # CONFIG_DEBUG_VM is not set +# CONFIG_DEBUG_VM_PGFLAGS is not set +# CONFIG_DEBUG_VM_RB is not set +# CONFIG_DEBUG_VM_VMACACHE is not set # CONFIG_DEBUG_WQ_FORCE_RR_CPU is not set # CONFIG_DEBUG_WW_MUTEX_SLOWPATH is not set # CONFIG_DEBUG_WX is not set @@ -1081,6 +1085,7 @@ CONFIG_DEBUG_KERNEL=y CONFIG_DEFAULT_CUBIC=y CONFIG_DEFAULT_DEADLINE=y CONFIG_DEFAULT_HOSTNAME="(none)" +CONFIG_DEFAULT_HUNG_TASK_TIMEOUT=120 CONFIG_DEFAULT_IOSCHED="deadline" CONFIG_DEFAULT_MMAP_MIN_ADDR=4096 # CONFIG_DEFAULT_NOOP is not set diff --git a/target/linux/generic/config-4.19 b/target/linux/generic/config-4.19 index 372cad70a6..153520c396 100644 --- a/target/linux/generic/config-4.19 +++ b/target/linux/generic/config-4.19 @@ -617,6 +617,7 @@ CONFIG_BLOCK=y # CONFIG_BONDING is not set # CONFIG_BOOKE_WDT is not set CONFIG_BOOKE_WDT_DEFAULT_TIMEOUT=3 +# CONFIG_BOOTPARAM_HUNG_TASK_PANIC is not set # CONFIG_BOOT_PRINTK_DELAY is not set CONFIG_BOOT_RAW=y CONFIG_BPF=y @@ -1131,6 +1132,9 @@ CONFIG_DEBUG_KERNEL=y # CONFIG_DEBUG_UART_BCM63XX is not set # CONFIG_DEBUG_VIRTUAL is not set # CONFIG_DEBUG_VM is not set +# CONFIG_DEBUG_VM_PGFLAGS is not set +# CONFIG_DEBUG_VM_RB is not set +# CONFIG_DEBUG_VM_VMACACHE is not set # CONFIG_DEBUG_WQ_FORCE_RR_CPU is not set # CONFIG_DEBUG_WW_MUTEX_SLOWPATH is not set # CONFIG_DEBUG_WX is not set @@ -1139,6 +1143,7 @@ CONFIG_DEBUG_KERNEL=y CONFIG_DEFAULT_CUBIC=y CONFIG_DEFAULT_DEADLINE=y CONFIG_DEFAULT_HOSTNAME="(none)" +CONFIG_DEFAULT_HUNG_TASK_TIMEOUT=120 CONFIG_DEFAULT_IOSCHED="deadline" CONFIG_DEFAULT_MMAP_MIN_ADDR=4096 # CONFIG_DEFAULT_NOOP is not set