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authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-06 09:30:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-06 09:30:52 -0700
commit4aed2fd8e3181fea7c09ba79cf64e7e3f4413bf9 (patch)
tree1f69733e5daab4915a76a41de0e4d1dc61e12cfb /lib
parent3a3527b6461b1298cc53ce72f336346739297ac8 (diff)
parentfc9ea5a1e53ee54f681e226d735008e2a6f8f470 (diff)
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (162 commits) tracing/kprobes: unregister_trace_probe needs to be called under mutex perf: expose event__process function perf events: Fix mmap offset determination perf, powerpc: fsl_emb: Restore setting perf_sample_data.period perf, powerpc: Convert the FSL driver to use local64_t perf tools: Don't keep unreferenced maps when unmaps are detected perf session: Invalidate last_match when removing threads from rb_tree perf session: Free the ref_reloc_sym memory at the right place x86,mmiotrace: Add support for tracing STOS instruction perf, sched migration: Librarize task states and event headers helpers perf, sched migration: Librarize the GUI class perf, sched migration: Make the GUI class client agnostic perf, sched migration: Make it vertically scrollable perf, sched migration: Parameterize cpu height and spacing perf, sched migration: Fix key bindings perf, sched migration: Ignore unhandled task states perf, sched migration: Handle ignored migrate out events perf: New migration tool overview tracing: Drop cpparg() macro perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call ... Fix up trivial conflicts in Makefile and drivers/cpufreq/cpufreq.c
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 e80d6bf1c43..ff87ddc4cbd 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