Loading Documentation/RCU/stallwarn.txt +17 −0 Original line number Diff line number Diff line Loading @@ -163,6 +163,23 @@ message will be about three times the interval between the beginning of the stall and the first message. Stall Warnings for Expedited Grace Periods If an expedited grace period detects a stall, it will place a message like the following in dmesg: INFO: rcu_sched detected expedited stalls on CPUs: { 1 2 6 } 26009 jiffies s: 1043 This indicates that CPUs 1, 2, and 6 have failed to respond to a reschedule IPI, that the expedited grace period has been going on for 26,009 jiffies, and that the expedited grace-period sequence counter is 1043. The fact that this last value is odd indicates that an expedited grace period is in flight. It is entirely possible to see stall warnings from normal and from expedited grace periods at about the same time from the same run. What Causes RCU CPU Stall Warnings? So your kernel printed an RCU CPU stall warning. The next question is Loading Loading
Documentation/RCU/stallwarn.txt +17 −0 Original line number Diff line number Diff line Loading @@ -163,6 +163,23 @@ message will be about three times the interval between the beginning of the stall and the first message. Stall Warnings for Expedited Grace Periods If an expedited grace period detects a stall, it will place a message like the following in dmesg: INFO: rcu_sched detected expedited stalls on CPUs: { 1 2 6 } 26009 jiffies s: 1043 This indicates that CPUs 1, 2, and 6 have failed to respond to a reschedule IPI, that the expedited grace period has been going on for 26,009 jiffies, and that the expedited grace-period sequence counter is 1043. The fact that this last value is odd indicates that an expedited grace period is in flight. It is entirely possible to see stall warnings from normal and from expedited grace periods at about the same time from the same run. What Causes RCU CPU Stall Warnings? So your kernel printed an RCU CPU stall warning. The next question is Loading
Paul E. McKenney <paulmck@linux.vnet.ibm.com>Paul E. McKenney <paulmck@linux.vnet.ibm.com>