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

On Tue, Mar 01, 2016 at 11:26:25AM +0100, Peter Zijlstra wrote:

$ make tags
  GEN     tags
ctags: Warning: drivers/acpi/processor_idle.c:64: null expansion of name pattern "\1"
ctags: Warning: drivers/xen/events/events_2l.c:41: null expansion of name pattern "\1"
ctags: Warning: kernel/locking/lockdep.c:151: null expansion of name pattern "\1"
ctags: Warning: kernel/rcu/rcutorture.c:133: null expansion of name pattern "\1"
ctags: Warning: kernel/rcu/rcutorture.c:135: null expansion of name pattern "\1"
ctags: Warning: kernel/workqueue.c:323: null expansion of name pattern "\1"
ctags: Warning: net/ipv4/syncookies.c:53: null expansion of name pattern "\1"
ctags: Warning: net/ipv6/syncookies.c:44: null expansion of name pattern "\1"
ctags: Warning: net/rds/page.c:45: null expansion of name pattern "\1"

Which are all the result of the DEFINE_PER_CPU pattern:

scripts/tags.sh:200:	'/\<DEFINE_PER_CPU([^,]*, *\([[:alnum:]_]*\)/\1/v/'
scripts/tags.sh:201:	'/\<DEFINE_PER_CPU_SHARED_ALIGNED([^,]*, *\([[:alnum:]_]*\)/\1/v/'

The below cures them. All except the workqueue one are within reasonable
distance of the 80 char limit. TJ do you have any preference on how to
fix the wq one, or shall we just not care its too long?

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

For rcutorture, the initializers are zero.  Would it make more sense to
remove the initializers completely in favor of C's default initialization
as shown below?

							Thanx, Paul

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

commit 9bd8e9f0c56cfc19ca5b68a73edd80b16bec4af8
Author: Paul E. McKenney [off-list ref]
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 [off-list ref]
    Signed-off-by: Paul E. McKenney [off-list ref]

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 1c2dc23ae07d..f5fd9acc0f9b 100644
--- a/kernel/rcu/rcutorture.c
+++ 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);
 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;