rcu: add grace-period age and more kthread state to tracing

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / Documentation / RCU / trace.txt

diff --git a/Documentation/RCU/trace.txt b/Documentation/RCU/trace.txt
index 40b530dd0fc7b977aaf69b857c5ce5178ddbcf76..fd4bffb6e8c92057ad8a7c739775d10148102ccd 100644 (file)
--- a/Documentation/RCU/trace.txt
+++ b/Documentation/RCU/trace.txt
@@ -159,8 +159,8 @@ o   "qs" gives an indication of the state of the callback queue
        the corresponding character is replaced by ".".
 
 o      "kt" is the per-CPU kernel-thread state.  The digit preceding
-       the slash is zero if there is no work pending and 1 otherwise.
-       The character after the slash is as follows:
+       the first slash is zero if there is no work pending and 1
+       otherwise.  The character between the slashes is as follows:
 
        "S"     The kernel thread is stopped, in other words, all
                CPUs corresponding to this rcu_node structure are
@@ -171,10 +171,18 @@ o "kt" is the per-CPU kernel-thread state.  The digit preceding
        "W"     The kernel thread is waiting because there is no work
                for it to do.
 
+       "O"     The kernel thread is waiting because it has been
+               forced off of its designated CPU or because its
+               ->cpus_allowed mask permits it to run on other than
+               its designated CPU.
+
        "Y"     The kernel thread is yielding to avoid hogging CPU.
 
        "?"     Unknown value, indicates a bug.
 
+       The number after the final slash is the CPU that the kthread
+       is actually running on.
+
 o      "b" is the batch limit for this CPU.  If more than this number
        of RCU callbacks is ready to invoke, then the remainder will
        be deferred.