* [PATCH] locking/atomic: atomic64: remove unusable atomics
@ 2021-11-26 11:59 Mark Rutland
2021-11-28 8:49 ` Boqun Feng
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Mark Rutland @ 2021-11-26 11:59 UTC (permalink / raw)
To: linux-kernel, Peter Zijlstra; +Cc: arnd, boqun.feng, lkp, mark.rutland, will
The generic atomic64 implementation provides:
* atomic64_and_return()
* atomic64_or_return()
* atomic64_xor_return()
... but none of these exist in the standard atomic64 API as described by
scripts/atomic/atomics.tbl, and none of these have prototypes exposed by
<asm-generic/atomic64.h>.
The lkp kernel test robot noted this results in warnings when building with
W=1:
lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_and_return' [-Wmissing-prototypes]
lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_or_return' [-Wmissing-prototypes]
lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_xor_return' [-Wmissing-prototypes]
This appears to have been a thinko in commit:
28aa2bda2211f432 ("locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()")
... where we grouped add/sub separately from and/ox/xor, so that we could avoid
implementing _return forms for the latter group, but forgot to remove
ATOMIC64_OP_RETURN() for that group.
This doesn't cause any functional problem, but it's pointless to build code
which cannot be used. Remove the unusable code. This does not affect add/sub,
for which _return forms will still be built.
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/202111120712.RtQHZohY-lkp@intel.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
---
lib/atomic64.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/lib/atomic64.c b/lib/atomic64.c
index 3df653994177..caf895789a1e 100644
--- a/lib/atomic64.c
+++ b/lib/atomic64.c
@@ -118,7 +118,6 @@ ATOMIC64_OPS(sub, -=)
#undef ATOMIC64_OPS
#define ATOMIC64_OPS(op, c_op) \
ATOMIC64_OP(op, c_op) \
- ATOMIC64_OP_RETURN(op, c_op) \
ATOMIC64_FETCH_OP(op, c_op)
ATOMIC64_OPS(and, &=)
@@ -127,7 +126,6 @@ ATOMIC64_OPS(xor, ^=)
#undef ATOMIC64_OPS
#undef ATOMIC64_FETCH_OP
-#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
s64 generic_atomic64_dec_if_positive(atomic64_t *v)
--
2.30.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] locking/atomic: atomic64: remove unusable atomics
2021-11-26 11:59 [PATCH] locking/atomic: atomic64: remove unusable atomics Mark Rutland
@ 2021-11-28 8:49 ` Boqun Feng
2021-12-08 18:20 ` Mark Rutland
2021-12-13 10:03 ` [tip: locking/core] locking/atomic: atomic64: Remove unusable atomic ops tip-bot2 for Mark Rutland
2 siblings, 0 replies; 5+ messages in thread
From: Boqun Feng @ 2021-11-28 8:49 UTC (permalink / raw)
To: Mark Rutland; +Cc: linux-kernel, Peter Zijlstra, arnd, lkp, will
On Fri, Nov 26, 2021 at 11:59:23AM +0000, Mark Rutland wrote:
> The generic atomic64 implementation provides:
>
> * atomic64_and_return()
> * atomic64_or_return()
> * atomic64_xor_return()
>
> ... but none of these exist in the standard atomic64 API as described by
> scripts/atomic/atomics.tbl, and none of these have prototypes exposed by
> <asm-generic/atomic64.h>.
>
> The lkp kernel test robot noted this results in warnings when building with
> W=1:
>
> lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_and_return' [-Wmissing-prototypes]
>
> lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_or_return' [-Wmissing-prototypes]
>
> lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_xor_return' [-Wmissing-prototypes]
>
> This appears to have been a thinko in commit:
>
> 28aa2bda2211f432 ("locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()")
>
> ... where we grouped add/sub separately from and/ox/xor, so that we could avoid
> implementing _return forms for the latter group, but forgot to remove
> ATOMIC64_OP_RETURN() for that group.
>
> This doesn't cause any functional problem, but it's pointless to build code
> which cannot be used. Remove the unusable code. This does not affect add/sub,
> for which _return forms will still be built.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Link: https://lore.kernel.org/r/202111120712.RtQHZohY-lkp@intel.com
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
FWIW
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Regards,
Boqun
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Boqun Feng <boqun.feng@gmail.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Will Deacon <will@kernel.org>
> ---
> lib/atomic64.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/lib/atomic64.c b/lib/atomic64.c
> index 3df653994177..caf895789a1e 100644
> --- a/lib/atomic64.c
> +++ b/lib/atomic64.c
> @@ -118,7 +118,6 @@ ATOMIC64_OPS(sub, -=)
> #undef ATOMIC64_OPS
> #define ATOMIC64_OPS(op, c_op) \
> ATOMIC64_OP(op, c_op) \
> - ATOMIC64_OP_RETURN(op, c_op) \
> ATOMIC64_FETCH_OP(op, c_op)
>
> ATOMIC64_OPS(and, &=)
> @@ -127,7 +126,6 @@ ATOMIC64_OPS(xor, ^=)
>
> #undef ATOMIC64_OPS
> #undef ATOMIC64_FETCH_OP
> -#undef ATOMIC64_OP_RETURN
> #undef ATOMIC64_OP
>
> s64 generic_atomic64_dec_if_positive(atomic64_t *v)
> --
> 2.30.2
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] locking/atomic: atomic64: remove unusable atomics
2021-11-26 11:59 [PATCH] locking/atomic: atomic64: remove unusable atomics Mark Rutland
2021-11-28 8:49 ` Boqun Feng
@ 2021-12-08 18:20 ` Mark Rutland
2021-12-08 18:44 ` Peter Zijlstra
2021-12-13 10:03 ` [tip: locking/core] locking/atomic: atomic64: Remove unusable atomic ops tip-bot2 for Mark Rutland
2 siblings, 1 reply; 5+ messages in thread
From: Mark Rutland @ 2021-12-08 18:20 UTC (permalink / raw)
To: linux-kernel, Peter Zijlstra; +Cc: arnd, boqun.feng, lkp, will
Peter, did you have any thoughts on this, or would you be happy to pick it as a
cleanup?
If there's anything on your queue that I can help to get out of the way, please
let me know!
Thanks,
Mark.
On Fri, Nov 26, 2021 at 11:59:23AM +0000, Mark Rutland wrote:
> The generic atomic64 implementation provides:
>
> * atomic64_and_return()
> * atomic64_or_return()
> * atomic64_xor_return()
>
> ... but none of these exist in the standard atomic64 API as described by
> scripts/atomic/atomics.tbl, and none of these have prototypes exposed by
> <asm-generic/atomic64.h>.
>
> The lkp kernel test robot noted this results in warnings when building with
> W=1:
>
> lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_and_return' [-Wmissing-prototypes]
>
> lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_or_return' [-Wmissing-prototypes]
>
> lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_xor_return' [-Wmissing-prototypes]
>
> This appears to have been a thinko in commit:
>
> 28aa2bda2211f432 ("locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()")
>
> ... where we grouped add/sub separately from and/ox/xor, so that we could avoid
> implementing _return forms for the latter group, but forgot to remove
> ATOMIC64_OP_RETURN() for that group.
>
> This doesn't cause any functional problem, but it's pointless to build code
> which cannot be used. Remove the unusable code. This does not affect add/sub,
> for which _return forms will still be built.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Link: https://lore.kernel.org/r/202111120712.RtQHZohY-lkp@intel.com
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Boqun Feng <boqun.feng@gmail.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Will Deacon <will@kernel.org>
> ---
> lib/atomic64.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/lib/atomic64.c b/lib/atomic64.c
> index 3df653994177..caf895789a1e 100644
> --- a/lib/atomic64.c
> +++ b/lib/atomic64.c
> @@ -118,7 +118,6 @@ ATOMIC64_OPS(sub, -=)
> #undef ATOMIC64_OPS
> #define ATOMIC64_OPS(op, c_op) \
> ATOMIC64_OP(op, c_op) \
> - ATOMIC64_OP_RETURN(op, c_op) \
> ATOMIC64_FETCH_OP(op, c_op)
>
> ATOMIC64_OPS(and, &=)
> @@ -127,7 +126,6 @@ ATOMIC64_OPS(xor, ^=)
>
> #undef ATOMIC64_OPS
> #undef ATOMIC64_FETCH_OP
> -#undef ATOMIC64_OP_RETURN
> #undef ATOMIC64_OP
>
> s64 generic_atomic64_dec_if_positive(atomic64_t *v)
> --
> 2.30.2
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] locking/atomic: atomic64: remove unusable atomics
2021-12-08 18:20 ` Mark Rutland
@ 2021-12-08 18:44 ` Peter Zijlstra
0 siblings, 0 replies; 5+ messages in thread
From: Peter Zijlstra @ 2021-12-08 18:44 UTC (permalink / raw)
To: Mark Rutland; +Cc: linux-kernel, arnd, boqun.feng, lkp, will
On Wed, Dec 08, 2021 at 06:20:47PM +0000, Mark Rutland wrote:
> Peter, did you have any thoughts on this, or would you be happy to pick it as a
> cleanup?
>
> If there's anything on your queue that I can help to get out of the way, please
> let me know!
>
I think it's good, it just got lost in this trainwreck of an inbox. I'll
try not to loose it again :-)
^ permalink raw reply [flat|nested] 5+ messages in thread
* [tip: locking/core] locking/atomic: atomic64: Remove unusable atomic ops
2021-11-26 11:59 [PATCH] locking/atomic: atomic64: remove unusable atomics Mark Rutland
2021-11-28 8:49 ` Boqun Feng
2021-12-08 18:20 ` Mark Rutland
@ 2021-12-13 10:03 ` tip-bot2 for Mark Rutland
2 siblings, 0 replies; 5+ messages in thread
From: tip-bot2 for Mark Rutland @ 2021-12-13 10:03 UTC (permalink / raw)
To: linux-tip-commits
Cc: kernel test robot, Mark Rutland, Peter Zijlstra (Intel),
Boqun Feng, x86, linux-kernel
The following commit has been merged into the locking/core branch of tip:
Commit-ID: 5fb6e8cf53b005d287d4c2d137a415ff7d025a81
Gitweb: https://git.kernel.org/tip/5fb6e8cf53b005d287d4c2d137a415ff7d025a81
Author: Mark Rutland <mark.rutland@arm.com>
AuthorDate: Fri, 26 Nov 2021 11:59:23
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 13 Dec 2021 10:56:09 +01:00
locking/atomic: atomic64: Remove unusable atomic ops
The generic atomic64 implementation provides:
* atomic64_and_return()
* atomic64_or_return()
* atomic64_xor_return()
... but none of these exist in the standard atomic64 API as described by
scripts/atomic/atomics.tbl, and none of these have prototypes exposed by
<asm-generic/atomic64.h>.
The lkp kernel test robot noted this results in warnings when building with
W=1:
lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_and_return' [-Wmissing-prototypes]
lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_or_return' [-Wmissing-prototypes]
lib/atomic64.c:82:5: warning: no previous prototype for 'generic_atomic64_xor_return' [-Wmissing-prototypes]
This appears to have been a thinko in commit:
28aa2bda2211f432 ("locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()")
... where we grouped add/sub separately from and/ox/xor, so that we could avoid
implementing _return forms for the latter group, but forgot to remove
ATOMIC64_OP_RETURN() for that group.
This doesn't cause any functional problem, but it's pointless to build code
which cannot be used. Remove the unusable code. This does not affect add/sub,
for which _return forms will still be built.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20211126115923.41489-1-mark.rutland@arm.com
---
lib/atomic64.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/lib/atomic64.c b/lib/atomic64.c
index 3df6539..caf8957 100644
--- a/lib/atomic64.c
+++ b/lib/atomic64.c
@@ -118,7 +118,6 @@ ATOMIC64_OPS(sub, -=)
#undef ATOMIC64_OPS
#define ATOMIC64_OPS(op, c_op) \
ATOMIC64_OP(op, c_op) \
- ATOMIC64_OP_RETURN(op, c_op) \
ATOMIC64_FETCH_OP(op, c_op)
ATOMIC64_OPS(and, &=)
@@ -127,7 +126,6 @@ ATOMIC64_OPS(xor, ^=)
#undef ATOMIC64_OPS
#undef ATOMIC64_FETCH_OP
-#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
s64 generic_atomic64_dec_if_positive(atomic64_t *v)
^ permalink raw reply related [flat|nested] 5+ messages in thread
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2021-11-26 11:59 [PATCH] locking/atomic: atomic64: remove unusable atomics Mark Rutland
2021-11-28 8:49 ` Boqun Feng
2021-12-08 18:20 ` Mark Rutland
2021-12-08 18:44 ` Peter Zijlstra
2021-12-13 10:03 ` [tip: locking/core] locking/atomic: atomic64: Remove unusable atomic ops tip-bot2 for Mark Rutland
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