From 05a4a95279311c3a4633b4277a5d21cfd616c6c7 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Wed, 12 Jul 2017 14:35:46 -0700 Subject: kernel/watchdog: split up config options Split SOFTLOCKUP_DETECTOR from LOCKUP_DETECTOR, and split HARDLOCKUP_DETECTOR_PERF from HARDLOCKUP_DETECTOR. LOCKUP_DETECTOR implies the general boot, sysctl, and programming interfaces for the lockup detectors. An architecture that wants to use a hard lockup detector must define HAVE_HARDLOCKUP_DETECTOR_PERF or HAVE_HARDLOCKUP_DETECTOR_ARCH. Alternatively an arch can define HAVE_NMI_WATCHDOG, which provides the minimum arch_touch_nmi_watchdog, and it otherwise does its own thing and does not implement the LOCKUP_DETECTOR interfaces. sparc is unusual in that it has started to implement some of the interfaces, but not fully yet. It should probably be converted to a full HAVE_HARDLOCKUP_DETECTOR_ARCH. [npiggin@gmail.com: fix] Link: http://lkml.kernel.org/r/20170617223522.66c0ad88@roar.ozlabs.ibm.com Link: http://lkml.kernel.org/r/20170616065715.18390-4-npiggin@gmail.com Signed-off-by: Nicholas Piggin Reviewed-by: Don Zickus Reviewed-by: Babu Moger Tested-by: Babu Moger [sparc] Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 45 ++++++++++++++++++++++++++++----------------- 1 file changed, 28 insertions(+), 17 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index f28f425..b0d01c6 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -778,34 +778,45 @@ config DEBUG_SHIRQ menu "Debug Lockups and Hangs" config LOCKUP_DETECTOR - bool "Detect Hard and Soft Lockups" + bool + +config SOFTLOCKUP_DETECTOR + bool "Detect Soft Lockups" depends on DEBUG_KERNEL && !S390 + select LOCKUP_DETECTOR help Say Y here to enable the kernel to act as a watchdog to detect - hard and soft lockups. + 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. +config HARDLOCKUP_DETECTOR_PERF + bool + select SOFTLOCKUP_DETECTOR + +# +# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard +# lockup detector rather than the perf based detector. +# +config HARDLOCKUP_DETECTOR + bool "Detect Hard Lockups" + depends on DEBUG_KERNEL && !S390 + depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH + select LOCKUP_DETECTOR + select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF + select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH + help + Say Y here to enable the kernel to act as a watchdog to detect + hard lockups. + 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 HARDLOCKUP_DETECTOR - def_bool y - depends on LOCKUP_DETECTOR && !HAVE_NMI_WATCHDOG - depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI - config BOOTPARAM_HARDLOCKUP_PANIC bool "Panic (Reboot) On Hard Lockups" depends on HARDLOCKUP_DETECTOR @@ -826,7 +837,7 @@ config BOOTPARAM_HARDLOCKUP_PANIC_VALUE config BOOTPARAM_SOFTLOCKUP_PANIC bool "Panic (Reboot) On Soft Lockups" - depends on LOCKUP_DETECTOR + depends on SOFTLOCKUP_DETECTOR help Say Y here to enable the kernel to panic on "soft lockups", which are bugs that cause the kernel to loop in kernel @@ -843,7 +854,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE int - depends on LOCKUP_DETECTOR + depends on SOFTLOCKUP_DETECTOR range 0 1 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC default 1 if BOOTPARAM_SOFTLOCKUP_PANIC @@ -851,7 +862,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE config DETECT_HUNG_TASK bool "Detect Hung Tasks" depends on DEBUG_KERNEL - default LOCKUP_DETECTOR + default SOFTLOCKUP_DETECTOR help Say Y here to enable the kernel to detect "hung tasks", which are bugs that cause the task to be stuck in -- cgit v1.1