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authorIngo Molnar <mingo@elte.hu>2010-08-05 08:45:05 +0200
committerIngo Molnar <mingo@elte.hu>2010-08-05 08:45:05 +0200
commit61be7fdec2f51b99570cd5dcc30c7848c8e56513 (patch)
tree4a73ee635bc3e35dc54f75caddd26ffb6238bb5c /lib
parentMerge branch 'core' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/opr... (diff)
parentkernel/watchdog: Initialize 'result' (diff)
downloadlinux-61be7fdec2f51b99570cd5dcc30c7848c8e56513.tar.xz
linux-61be7fdec2f51b99570cd5dcc30c7848c8e56513.zip
Merge branch 'perf/nmi' into perf/core
Conflicts: kernel/Makefile Merge reason: Add the now complete topic, fix the conflict. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug35
1 files changed, 20 insertions, 15 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index e722e9d62221..e2cd7fbf31c0 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -152,28 +152,33 @@ config DEBUG_SHIRQ
Drivers ought to be able to handle interrupts coming in at those
points; some don't and need to be caught.
-config DETECT_SOFTLOCKUP
- bool "Detect Soft Lockups"
+config LOCKUP_DETECTOR
+ bool "Detect Hard and Soft Lockups"
depends on DEBUG_KERNEL && !S390
- default y
help
- Say Y here to enable the kernel to detect "soft lockups",
- which are bugs that cause the kernel to loop in kernel
+ 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 60 seconds, without giving other tasks a
- chance to run.
+ chance to run. The current stack trace is displayed upon
+ detection and the system will stay locked up.
- When a soft-lockup is detected, the kernel will print the
- current stack trace (which you should report), but the
- system will stay locked up. This feature has negligible
- overhead.
+ Hardlockups are bugs that cause the CPU to loop in kernel mode
+ for more than 60 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 10-12 seconds.
+ An NMI is generated every 60 seconds or so to check for hardlockups.
- (Note that "hard lockups" are separate type of bugs that
- can be detected via the NMI-watchdog, on platforms that
- support it.)
+config HARDLOCKUP_DETECTOR
+ def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI
config BOOTPARAM_SOFTLOCKUP_PANIC
bool "Panic (Reboot) On Soft Lockups"
- depends on DETECT_SOFTLOCKUP
+ depends on LOCKUP_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
@@ -190,7 +195,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC
config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
int
- depends on DETECT_SOFTLOCKUP
+ depends on LOCKUP_DETECTOR
range 0 1
default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
default 1 if BOOTPARAM_SOFTLOCKUP_PANIC