Re: [RFC][PATCH] tags: Fix DEFINE_PER_CPU expansions

From: Paul E. McKenney
Date: Tue Mar 01 2016 - 17:01:25 EST


On Tue, Mar 01, 2016 at 10:34:44PM +0100, Peter Zijlstra wrote:
> On Tue, Mar 01, 2016 at 08:56:50AM -0800, Paul E. McKenney wrote:
> > +++ b/kernel/rcu/rcutorture.c
> > @@ -131,9 +131,9 @@ static unsigned long rcu_torture_current_version;
> > static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
> > static DEFINE_SPINLOCK(rcu_torture_lock);
> > static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
> > - rcu_torture_count) = { 0 };
> > + rcu_torture_count);
>
> So the problem I was fixing is that the ctags regex needs the second
> argument for the DEFINE_PER_CPU() macro on the same line.
>
> So it would still need to be:
>
> static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count);
>
> > static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
> > - rcu_torture_batch) = { 0 };
> > + rcu_torture_batch);
> > static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
> > static atomic_t n_rcu_torture_alloc;
> > static atomic_t n_rcu_torture_alloc_fail;

Ah, like this, then.

Thanx, Paul

------------------------------------------------------------------------

commit 55d4929acdc66f00f27d79bfe273eeda01ec899f
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Date: Tue Mar 1 08:52:19 2016 -0800

rcutorture: Remove redundant initialization to zero

The current code initializes the global per-CPU variables
rcu_torture_count and rcu_torture_batch to zero. However, C does this
initialization by default, and explicit initialization of per-CPU
variables now needs a different syntax if "make tags" is to work.
This commit therefore removes the initialization.

Reported-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 1c2dc23ae07d..e75557368c04 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -130,10 +130,8 @@ static struct rcu_torture __rcu *rcu_torture_current;
static unsigned long rcu_torture_current_version;
static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
static DEFINE_SPINLOCK(rcu_torture_lock);
-static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
- rcu_torture_count) = { 0 };
-static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
- rcu_torture_batch) = { 0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count);
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch);
static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
static atomic_t n_rcu_torture_alloc;
static atomic_t n_rcu_torture_alloc_fail;