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

2016-03-01 Thread Paul E. McKenney 
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 
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 
Signed-off-by: Paul E. McKenney 

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;

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

2016-03-01 Thread Rafael J. Wysocki 
On Tue, Mar 1, 2016 at 11:26 AM, 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:'/\ scripts/tags.sh:201:'/\ *\([[:alnum:]_]*\)/\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) 
> ---
>  drivers/acpi/processor_idle.c  | 4 ++--
>  drivers/xen/events/events_2l.c | 5 +++--
>  kernel/locking/lockdep.c   | 3 +--
>  kernel/rcu/rcutorture.c| 6 ++
>  kernel/workqueue.c | 3 +--
>  net/ipv4/syncookies.c  | 3 +--
>  net/ipv6/syncookies.c  | 3 +--
>  net/rds/page.c | 4 ++--
>  8 files changed, 13 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 175c86bee3a9..9ca2b2fefd76 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -61,8 +61,8 @@ module_param(latency_factor, uint, 0644);
>
>  static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
>
> -static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
> -   acpi_cstate);
> +static
> +DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
>
>  static int disabled_by_idle_boot_param(void)
>  {

For the above:

Acked-by: Rafael J. Wysocki

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

2016-03-01 Thread Peter Zijlstra 
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;
>

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

2016-03-01 Thread Paul E. McKenney 
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:  '/\ scripts/tags.sh:201:  '/\ *\([[:alnum:]_]*\)/\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) 

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 
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 
Signed-off-by: Paul E. McKenney 

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;

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

2016-03-01 Thread Tejun Heo 
Hello,

On Tue, Mar 01, 2016 at 07:18:42PM +0100, Peter Zijlstra wrote:
> > Urgh... I really hate the fact that we're putting on arbitrary
> > formatting constraints to compensate for shortcomings in an
> > out-of-line utility.
> 
> Yes it does.
> 
> I'm not too bothered if you don't want to fix this, I just figured I'd
> have a stab at fixing all this, since I regularly run 'make tags' and
> got tired of seeing the warns.

I use cscope so haven't noticed them.

> > Can't it do multiline regex?
> 
> Apparently not:
> 
>   https://sourceforge.net/p/ctags/feature-requests/38/

That's unfortunate.  Ah well, it's only several spots and isn't a big
deal one way or the other.  Occasional >80 lines are fine by me.
Please feel free to add

 Acked-by: Tejun Heo 

Thanks.

-- 
tejun

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

2016-03-01 Thread Peter Zijlstra 
On Tue, Mar 01, 2016 at 11:37:07AM -0500, Tejun Heo wrote:
> Hello, Peter.
> 
> 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:'/\ > *\([[:alnum:]_]*\)/\1/v/'
> > scripts/tags.sh:201:'/\ > *\([[:alnum:]_]*\)/\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?
> 
> Urgh... I really hate the fact that we're putting on arbitrary
> formatting constraints to compensate for shortcomings in an
> out-of-line utility.

Yes it does.

I'm not too bothered if you don't want to fix this, I just figured I'd
have a stab at fixing all this, since I regularly run 'make tags' and
got tired of seeing the warns.

> Can't it do multiline regex?

Apparently not:

  https://sourceforge.net/p/ctags/feature-requests/38/

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

2016-03-01 Thread David Miller 
From: Peter Zijlstra 
Date: Tue, 1 Mar 2016 11:26:25 +0100

> 
> $ 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:  '/\ scripts/tags.sh:201:  '/\ *\([[:alnum:]_]*\)/\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) 

For the networking bits:

Acked-by: David S. Miller

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

2016-03-01 Thread Tejun Heo 
Hello, Peter.

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:  '/\ scripts/tags.sh:201:  '/\ *\([[:alnum:]_]*\)/\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?

Urgh... I really hate the fact that we're putting on arbitrary
formatting constraints to compensate for shortcomings in an
out-of-line utility.  Can't it do multiline regex?

Thanks.

-- 
tejun

[RFC][PATCH] tags: Fix DEFINE_PER_CPU expansions

2016-03-01 Thread Peter Zijlstra 

$ 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:'/\
---
 drivers/acpi/processor_idle.c  | 4 ++--
 drivers/xen/events/events_2l.c | 5 +++--
 kernel/locking/lockdep.c   | 3 +--
 kernel/rcu/rcutorture.c| 6 ++
 kernel/workqueue.c | 3 +--
 net/ipv4/syncookies.c  | 3 +--
 net/ipv6/syncookies.c  | 3 +--
 net/rds/page.c | 4 ++--
 8 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 175c86bee3a9..9ca2b2fefd76 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -61,8 +61,8 @@ module_param(latency_factor, uint, 0644);
 
 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
 
-static DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX],
-   acpi_cstate);
+static
+DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
 
 static int disabled_by_idle_boot_param(void)
 {
diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c
index 7dd46312c180..403fe3955393 100644
--- a/drivers/xen/events/events_2l.c
+++ b/drivers/xen/events/events_2l.c
@@ -38,8 +38,9 @@
 /* Find the first set bit in a evtchn mask */
 #define EVTCHN_FIRST_BIT(w) find_first_bit(BM(&(w)), BITS_PER_EVTCHN_WORD)
 
-static DEFINE_PER_CPU(xen_ulong_t [EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD],
- cpu_evtchn_mask);
+#define EVTCHN_MASK_SIZE (EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD)
+
+static DEFINE_PER_CPU(xen_ulong_t [EVTCHN_MASK_SIZE], cpu_evtchn_mask);
 
 static unsigned evtchn_2l_max_channels(void)
 {
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 3261214323fa..9599bc7742a9 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -148,8 +148,7 @@ static inline struct lock_class *hlock_class(struct 
held_lock *hlock)
 }
 
 #ifdef CONFIG_LOCK_STAT
-static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS],
- cpu_lock_stats);
+static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], 
cpu_lock_stats);
 
 static inline u64 lockstat_clock(void)
 {
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index d2988d047d66..4d5cc6aa7e1e 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) = { 
0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = { 
0 };
 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;
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 7ff5dc7d2ac5..16e13d8628a3 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -320,8 +320,7 @@ static bool wq_debug_force_rr_cpu = false;
 module_param_named(debug_force_rr_cpu, wq_debug_force_rr_cpu, bool, 0644);
 
 /* the per-cpu worker pools */
-static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS],
-cpu_worker_pools);
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS], 
cpu_worker_pools);
 
 static DEFINE_IDR(worker_pool_idr);/* PR: idr of all pools */
 
diff --git a/net/ipv4/syncookies.c