rcu: Rename rcu_check_callbacks() to rcu_sched_clock_irq()

The name rcu_check_callbacks() arguably made sense back in the early
2000s when RCU was quite a bit simpler than it is today, but it has
become quite misleading, especially with the advent of dyntick-idle
and NO_HZ_FULL.  The rcu_check_callbacks() function is RCU's hook into
the scheduling-clock interrupt, and is now but one of many ways that
callbacks get promoted to invocable state.

This commit therefore changes the name to rcu_sched_clock_irq(),
which is the same number of characters and clearly indicates this
function's relation to the rest of the Linux kernel.  In addition, for
the sake of consistency, rcu_flavor_check_callbacks() is also renamed
to rcu_flavor_sched_clock_irq().

While in the area, the header comments for both functions are reworked.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>

4 files changed, 6 insertions, 6 deletions

diff --git a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html
index e4d94fba6c89..a3acfd49255f 100644
--- a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html
+++ b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html
@@ -485,7 +485,7 @@ section that the grace period must wait on.
 noted by <tt>rcu_node_context_switch()</tt> on the left.
 On the other hand, if the CPU takes a scheduler-clock interrupt
 while executing in usermode, a quiescent state will be noted by
-<tt>rcu_check_callbacks()</tt> on the right.
+<tt>rcu_sched_clock_irq()</tt> on the right.
 Either way, the passage through a quiescent state will be noted
 in a per-CPU variable.
 
@@ -651,7 +651,7 @@ to end.
 These callbacks are identified by <tt>rcu_advance_cbs()</tt>,
 which is usually invoked by <tt>__note_gp_changes()</tt>.
 As shown in the diagram below, this invocation can be triggered by
-the scheduling-clock interrupt (<tt>rcu_check_callbacks()</tt> on
+the scheduling-clock interrupt (<tt>rcu_sched_clock_irq()</tt> on
 the left) or by idle entry (<tt>rcu_cleanup_after_idle()</tt> on
 the right, but only for kernels build with
 <tt>CONFIG_RCU_FAST_NO_HZ=y</tt>).
diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg
index 832408313d93..3fcf0c17cef2 100644
--- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg
+++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg
@@ -349,7 +349,7 @@
        font-weight="bold"
        font-size="192"
        id="text202-7-5"
-       style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_check_callbacks()</text>
+       style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_sched_clock_irq()</text>
     <rect
        x="7069.6187"
        y="5087.4678"
diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg
index acd73c7ad0f4..f0bbe6f8d729 100644
--- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg
+++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg
@@ -3902,7 +3902,7 @@
          font-style="normal"
          y="-4418.6582"
          x="3745.7725"
-         xml:space="preserve">rcu_check_callbacks()</text>
+         xml:space="preserve">rcu_sched_clock_irq()</text>
     </g>
     <g
        transform="translate(-850.30204,55463.106)"
@@ -4968,7 +4968,7 @@
        font-weight="bold"
        font-size="192"
        id="text202-7-5-19"
-       style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_check_callbacks()</text>
+       style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_sched_clock_irq()</text>
     <rect
        x="5314.2671"
        y="82817.688"
diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-qs.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-qs.svg
index 149bec2a4493..3596ffdd4685 100644
--- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-qs.svg
+++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-qs.svg
@@ -775,7 +775,7 @@
          font-style="normal"
          y="-4418.6582"
          x="3745.7725"
-         xml:space="preserve">rcu_check_callbacks()</text>
+         xml:space="preserve">rcu_sched_clock_irq()</text>
     </g>
     <g
        transform="translate(399.7744,828.86448)"