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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-12-17 08:35:02 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-01-15 23:33:15 -0800 |
| commit | fb81a44b88e6173ed0f6e9d6a1afa5305fb63f6e (patch) | |
| tree | faa68798164b89dd6d37a9a591e62e9dfc7afdad /Documentation/RCU | |
| parent | 5cd37193ce8539be1e6ef76be226f4bcc984e0f5 (diff) | |
| download | lwn-fb81a44b88e6173ed0f6e9d6a1afa5305fb63f6e.tar.gz lwn-fb81a44b88e6173ed0f6e9d6a1afa5305fb63f6e.zip | |
rcu: Add GP-kthread-starvation checks to CPU stall warnings
This commit adds a message that is printed if the relevant grace-period
kthread has not been able to run for the two seconds preceding the
stall warning. (The two seconds is double the maximum interval between
successive bouts of quiescent-state forcing.)
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'Documentation/RCU')
| -rw-r--r-- | Documentation/RCU/stallwarn.txt | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/RCU/stallwarn.txt b/Documentation/RCU/stallwarn.txt index 55f9707fe60a..53e7d2856db6 100644 --- a/Documentation/RCU/stallwarn.txt +++ b/Documentation/RCU/stallwarn.txt @@ -152,6 +152,15 @@ no non-lazy callbacks ("." is printed otherwise, as shown above) and "D" indicates that dyntick-idle processing is enabled ("." is printed otherwise, for example, if disabled via the "nohz=" kernel boot parameter). +If the relevant grace-period kthread has been unable to run prior to +the stall warning, the following additional line is printed: + + rcu_preempt kthread starved for 2023 jiffies! + +Starving the grace-period kthreads of CPU time can of course result in +RCU CPU stall warnings even when all CPUs and tasks have passed through +the required quiescent states. + Multiple Warnings From One Stall |