[PATCH] RDS: IB: Use DEFINE_PER_CPU_SHARED_ALIGNED for rds_ib_stats

Clang warns when two declarations' section attributes don't match.

net/rds/ib_stats.c:40:1: warning: section does not match previous
declaration [-Wsection]
DEFINE_PER_CPU_SHARED_ALIGNED(struct rds_ib_statistics, rds_ib_stats);
^
./include/linux/percpu-defs.h:142:2: note: expanded from macro
'DEFINE_PER_CPU_SHARED_ALIGNED'
        DEFINE_PER_CPU_SECTION(type, name,
PER_CPU_SHARED_ALIGNED_SECTION) \
        ^
./include/linux/percpu-defs.h:93:9: note: expanded from macro
'DEFINE_PER_CPU_SECTION'
        extern __PCPU_ATTRS(sec) __typeof__(type) name;
\
               ^
./include/linux/percpu-defs.h:49:26: note: expanded from macro
'__PCPU_ATTRS'
        __percpu __attribute__((section(PER_CPU_BASE_SECTION sec)))
\
                                ^
net/rds/ib.h:446:1: note: previous attribute is here
DECLARE_PER_CPU(struct rds_ib_statistics, rds_ib_stats);
^
./include/linux/percpu-defs.h:111:2: note: expanded from macro
'DECLARE_PER_CPU'
        DECLARE_PER_CPU_SECTION(type, name, "")
        ^
./include/linux/percpu-defs.h:87:9: note: expanded from macro
'DECLARE_PER_CPU_SECTION'
        extern __PCPU_ATTRS(sec) __typeof__(type) name
               ^
./include/linux/percpu-defs.h:49:26: note: expanded from macro
'__PCPU_ATTRS'
        __percpu __attribute__((section(PER_CPU_BASE_SECTION sec)))
\
                                ^
1 warning generated.

The initial definition was added in commit ec16227e1414 ("RDS/IB:
Infiniband transport") and the cache aligned definition was added in
commit e6babe4cc4ce ("RDS/IB: Stats and sysctls") right after. The
definition probably should have been updated in net/rds/ib.h, which is
what this patch does.

Link: https://github.com/ClangBuiltLinux/linux/issues/114
Signed-off-by: Nathan Chancellor <redacted>
---
 net/rds/ib.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/rds/ib.h b/net/rds/ib.h
index 73427ff439f9..fd483760c910 100644
--- a/net/rds/ib.h
+++ b/net/rds/ib.h

@@ -443,7 +443,7 @@ int rds_ib_send_grab_credits(struct rds_ib_connection *ic, u32 wanted,
 int rds_ib_xmit_atomic(struct rds_connection *conn, struct rm_atomic_op *op);
 
 /* ib_stats.c */
-DECLARE_PER_CPU(struct rds_ib_statistics, rds_ib_stats);
+DEFINE_PER_CPU_SHARED_ALIGNED(struct rds_ib_statistics, rds_ib_stats);
 #define rds_ib_stats_inc(member) rds_stats_inc_which(rds_ib_stats, member)
 #define rds_ib_stats_add(member, count) \
 		rds_stats_add_which(rds_ib_stats, member, count)

-- 
2.19.0

On 9/21/2018 11:04 AM, Nathan Chancellor wrote:

Clang warns when two declarations' section attributes don't match.

net/rds/ib_stats.c:40:1: warning: section does not match previous
declaration [-Wsection]
DEFINE_PER_CPU_SHARED_ALIGNED(struct rds_ib_statistics, rds_ib_stats);
^
./include/linux/percpu-defs.h:142:2: note: expanded from macro
'DEFINE_PER_CPU_SHARED_ALIGNED'
         DEFINE_PER_CPU_SECTION(type, name,
PER_CPU_SHARED_ALIGNED_SECTION) \
         ^
./include/linux/percpu-defs.h:93:9: note: expanded from macro
'DEFINE_PER_CPU_SECTION'
         extern __PCPU_ATTRS(sec) __typeof__(type) name;
\
                ^
./include/linux/percpu-defs.h:49:26: note: expanded from macro
'__PCPU_ATTRS'
         __percpu __attribute__((section(PER_CPU_BASE_SECTION sec)))
\
                                 ^
net/rds/ib.h:446:1: note: previous attribute is here
DECLARE_PER_CPU(struct rds_ib_statistics, rds_ib_stats);
^
./include/linux/percpu-defs.h:111:2: note: expanded from macro
'DECLARE_PER_CPU'
         DECLARE_PER_CPU_SECTION(type, name, "")
         ^
./include/linux/percpu-defs.h:87:9: note: expanded from macro
'DECLARE_PER_CPU_SECTION'
         extern __PCPU_ATTRS(sec) __typeof__(type) name
                ^
./include/linux/percpu-defs.h:49:26: note: expanded from macro
'__PCPU_ATTRS'
         __percpu __attribute__((section(PER_CPU_BASE_SECTION sec)))
\
                                 ^
1 warning generated.

The initial definition was added in commit ec16227e1414 ("RDS/IB:
Infiniband transport") and the cache aligned definition was added in
commit e6babe4cc4ce ("RDS/IB: Stats and sysctls") right after. The
definition probably should have been updated in net/rds/ib.h, which is
what this patch does.

Link: https://github.com/ClangBuiltLinux/linux/issues/114
Signed-off-by: Nathan Chancellor <redacted>
---

Looks fine. Thanks !!

Acked-by: Santosh Shilimkar <redacted>

On Fri, Sep 21, 2018 at 11:04:51AM -0700, Nathan Chancellor wrote:

I have sent a v2 because this should be DECLARE_PER_CPU_SHARED_ALIGNED,
not DEFINE (thanks to 0day for catching it).

I will make sure the '--in-reply-to' option in the future.

Nathan

 #define rds_ib_stats_inc(member) rds_stats_inc_which(rds_ib_stats, member)
 #define rds_ib_stats_add(member, count) \
 		rds_stats_add_which(rds_ib_stats, member, count)
-- 
2.19.0

From: Nathan Chancellor <redacted>
Date: Sat, 22 Sep 2018 23:44:45 -0700

I have sent a v2 because this should be DECLARE_PER_CPU_SHARED_ALIGNED,
not DEFINE (thanks to 0day for catching it).

Your first version was already applied to the networking GIT tree, so
you will need to submit a relative fixup with a proper "Fixes: " tag.

From: David Miller <davem@davemloft.net>
Date: Sun, 23 Sep 2018 12:19:27 -0700 (PDT)

From: Nathan Chancellor <redacted>
Date: Sat, 22 Sep 2018 23:44:45 -0700

quoted

I have sent a v2 because this should be DECLARE_PER_CPU_SHARED_ALIGNED,
not DEFINE (thanks to 0day for catching it).

Your first version was already applied to the networking GIT tree, so
you will need to submit a relative fixup with a proper "Fixes: " tag.

Nevermind, I took care of it myself.

====================

From 16fdf8ba98391650ce4bc4f3f71629d8a413bc21 Mon Sep 17 00:00:00 2001

From: "David S. Miller" <davem@davemloft.net>
Date: Sun, 23 Sep 2018 12:25:15 -0700
Subject: [PATCH] rds: Fix build regression.

Use DECLARE_* not DEFINE_*

Fixes: 8360ed6745df ("RDS: IB: Use DEFINE_PER_CPU_SHARED_ALIGNED for rds_ib_stats")
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/rds/ib.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/rds/ib.h b/net/rds/ib.h
index fd483760c910..71ff356ee702 100644
--- a/net/rds/ib.h
+++ b/net/rds/ib.h

@@ -443,7 +443,7 @@ int rds_ib_send_grab_credits(struct rds_ib_connection *ic, u32 wanted,
 int rds_ib_xmit_atomic(struct rds_connection *conn, struct rm_atomic_op *op);
 
 /* ib_stats.c */
-DEFINE_PER_CPU_SHARED_ALIGNED(struct rds_ib_statistics, rds_ib_stats);
+DECLARE_PER_CPU_SHARED_ALIGNED(struct rds_ib_statistics, rds_ib_stats);
 #define rds_ib_stats_inc(member) rds_stats_inc_which(rds_ib_stats, member)
 #define rds_ib_stats_add(member, count) \
 		rds_stats_add_which(rds_ib_stats, member, count)

-- 
2.13.6

On Sun, Sep 23, 2018 at 12:19:27PM -0700, David Miller wrote:

From: Nathan Chancellor <redacted>
Date: Sat, 22 Sep 2018 23:44:45 -0700

quoted

I have sent a v2 because this should be DECLARE_PER_CPU_SHARED_ALIGNED,
not DEFINE (thanks to 0day for catching it).

Your first version was already applied to the networking GIT tree, so
you will need to submit a relative fixup with a proper "Fixes: " tag.

Hi David,

My apologies, I didn't receive an email saying my patch was applied so I
didn't think to check your tree. I'll be better about this in the
future.

Thank you for fixing this up yourself and all your patience, sorry for
all the noise!

Nathan