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| author | Andrea Parri <andrea.parri@amarulasolutions.com> | 2019-05-27 10:49:57 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-06-13 15:38:34 -0700 |
| commit | 9129b017b54dab09eb69b7269026243156e5188e (patch) | |
| tree | 581b8b644eea503a0a7fb9765217871e11fc2272 /Documentation | |
| parent | 6da9f775175e516fc7229ceaa9b54f8f56aa7924 (diff) | |
| download | linux-9129b017b54dab09eb69b7269026243156e5188e.tar.gz linux-9129b017b54dab09eb69b7269026243156e5188e.tar.bz2 linux-9129b017b54dab09eb69b7269026243156e5188e.zip | |
rcu: Don't return a value from rcu_assign_pointer()
Quoting Paul [1]:
"Given that a quick (and perhaps error-prone) search of the uses
of rcu_assign_pointer() in v5.1 didn't find a single use of the
return value, let's please instead change the documentation and
implementation to eliminate the return value."
[1] https://lkml.kernel.org/r/20190523135013.GL28207@linux.ibm.com
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: rcu@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/RCU/whatisRCU.txt | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 981651a8b65d..7e1a8721637a 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -212,7 +212,7 @@ synchronize_rcu() rcu_assign_pointer() - typeof(p) rcu_assign_pointer(p, typeof(p) v); + void rcu_assign_pointer(p, typeof(p) v); Yes, rcu_assign_pointer() -is- implemented as a macro, though it would be cool to be able to declare a function in this manner. @@ -220,9 +220,9 @@ rcu_assign_pointer() The updater uses this function to assign a new value to an RCU-protected pointer, in order to safely communicate the change - in value from the updater to the reader. This function returns - the new value, and also executes any memory-barrier instructions - required for a given CPU architecture. + in value from the updater to the reader. This macro does not + evaluate to an rvalue, but it does execute any memory-barrier + instructions required for a given CPU architecture. Perhaps just as important, it serves to document (1) which pointers are protected by RCU and (2) the point at which a |