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| author | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-12-12 21:32:06 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-01-26 00:29:59 +0100 |
| commit | 2ccaff10f71307ad4f75ce673b815d3fe6254e3d (patch) | |
| tree | 9d6d8064a44db829f879802af697a13a49868074 /Documentation/admin-guide | |
| parent | rcu: Protect rcu_check_gp_kthread_starvation() access to ->gp_flags (diff) | |
| download | linux-2ccaff10f71307ad4f75ce673b815d3fe6254e3d.tar.xz linux-2ccaff10f71307ad4f75ce673b815d3fe6254e3d.zip | |
rcu: Add sysrq rcu_node-dump capability
Life is hard if RCU manages to get stuck without triggering RCU CPU
stall warnings or triggering the rcu_check_gp_start_stall() checks
for failing to start a grace period. This commit therefore adds a
boot-time-selectable sysrq key (commandeering "y") that allows manually
dumping Tree RCU state. The new rcutree.sysrq_rcu kernel boot parameter
must be set for this sysrq to be available.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b799bcf67d7b..b0dbb2fa401f 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3721,6 +3721,11 @@ This wake_up() will be accompanied by a WARN_ONCE() splat and an ftrace_dump(). + rcutree.sysrq_rcu= [KNL] + Commandeer a sysrq key to dump out Tree RCU's + rcu_node tree with an eye towards determining + why a new grace period has not yet started. + rcuperf.gp_async= [KNL] Measure performance of asynchronous grace-period primitives such as call_rcu(). |