|author||Paul E. McKenney <firstname.lastname@example.org>||2010-07-21 08:05:56 -0700|
|committer||Paul E. McKenney <email@example.com>||2010-08-19 17:18:04 -0700|
rcu: Allow RCU CPU stall warnings to be off at boot, but manually enablable
Currently, if RCU CPU stall warnings are enabled, they are enabled immediately upon boot. They can be manually disabled via /sys (and also re-enabled via /sys), and are automatically disabled upon panic. However, some users need RCU CPU stalls to be disabled at boot time, but to be enabled without rebuilding/rebooting. For example, someone running a real-time application in production might not want the additional latency of RCU CPU stall detection in normal operation, but might need to enable it at any point for fault isolation purposes. This commit therefore provides a new CONFIG_RCU_CPU_STALL_DETECTOR_RUNNABLE kernel configuration parameter that maintains the current behavior (enable at boot) by default, but allows a kernel to be configured with RCU CPU stall detection built into the kernel, but disabled at boot time. Requested-by: Clark Williams <firstname.lastname@example.org> Requested-by: John Kacur <email@example.com> Signed-off-by: Paul E. McKenney <firstname.lastname@example.org>
Diffstat (limited to 'lib')
1 files changed, 13 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b5005b76210..52c2172dff1 100644
@@ -856,6 +856,19 @@ config RCU_CPU_STALL_TIMEOUT
RCU grace period persists, additional CPU stall warnings are
printed at more widely spaced intervals.
+ bool "RCU CPU stall checking starts automatically at boot"
+ depends on RCU_CPU_STALL_DETECTOR
+ default y
+ If set, start checking for RCU CPU stalls immediately on
+ boot. Otherwise, RCU CPU stall checking must be manually
+ Say Y if you are unsure.
+ Say N if you wish to suppress RCU CPU stall checking during boot.
bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR"
depends on RCU_CPU_STALL_DETECTOR && TREE_PREEMPT_RCU