linux-hardened/Documentation/RCU
Paul E. McKenney 0ac3d136b2 rcu: add callback-queue information to rcudata output
This commit adds an indication of the state of the callback queue using
a string of four characters following the "ql=" integer queue length.
The first character is "N" if there are callbacks that have been
queued that are not yet ready to be handled by the next grace period, or
"." otherwise.  The second character is "R" if there are callbacks queued
that are ready to be handled by the next grace period, or "." otherwise.
The third character is "W" if there are callbacks waiting for the current
grace period, or "." otherwise.  Finally, the fourth character is "D"
if there are callbacks that have been handled by a prior grace period
and are waiting to be invoked, or ".".

Note that callbacks that are in the process of being invoked are
not shown.  These callbacks would have been removed from the rcu_data
structure's list by rcu_do_batch() prior to being executed.  (These
callbacks are also not reflected in the "ql=" total, FWIW.)

Also, document the new callback-queue trace information.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-05-05 23:16:56 -07:00
..
00-INDEX rcu: Remove conditional compilation for RCU CPU stall warnings 2011-05-05 23:16:54 -07:00
arrayRCU.txt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
checklist.txt rcu: document ways of stalling updates in low-memory situations 2010-08-20 09:00:14 -07:00
listRCU.txt Doc: Fix wrong API example usage of call_rcu(). 2009-04-02 01:33:50 -07:00
lockdep.txt rcu: Update docs for rcu_access_pointer and rcu_dereference_protected 2010-04-14 12:20:12 +02:00
NMI-RCU.txt rcu: Update docs for rcu_access_pointer and rcu_dereference_protected 2010-04-14 12:20:12 +02:00
rcu.txt rcu: 1Q2010 update for RCU documentation 2010-01-16 10:25:22 +01:00
rcubarrier.txt rcu: Add synchronize_sched_expedited() rcutorture doc + updates 2009-07-03 10:02:29 +02:00
rculist_nulls.txt netfilter: nf_conntrack: nf_conntrack_alloc() fixes 2009-07-16 14:03:40 +02:00
rcuref.txt doc/RCU: fix pseudocode in rcuref.txt 2008-09-10 08:36:07 +02:00
RTFP.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
stallwarn.txt rcu: Remove conditional compilation for RCU CPU stall warnings 2011-05-05 23:16:54 -07:00
torture.txt sched: replace migration_thread with cpu_stop 2010-05-06 18:49:21 +02:00
trace.txt rcu: add callback-queue information to rcudata output 2011-05-05 23:16:56 -07:00
UP.txt rcu: Add synchronize_sched_expedited() rcutorture doc + updates 2009-07-03 10:02:29 +02:00
whatisRCU.txt rcu: add documentation saying which RCU flavor to choose 2011-03-04 08:05:25 -08:00