Searched hist:cea43147905f1c2b7b48104a5304cf5229f45bec (Results 1 – 3 of 3) sorted by relevance
| /openbmc/linux/arch/arc/include/asm/ |
| H A D | smp.h | diff cea43147905f1c2b7b48104a5304cf5229f45bec Tue Sep 04 18:11:29 CDT 2018 Vineet Gupta <vgupta@kernel.org> ARC: switch to generic bitops
- !LLSC now only needs a single spinlock for atomics and bitops
- Some codegen changes (slight bloat) with generic bitops
1. code increase due to LD-check-atomic paradigm vs. unconditonal
atomic (but dirty'ing the cache line even if set already).
So despite increase, generic is right thing to do.
2. code decrease (but use of costlier instructions such as DIV vs.
shifts based math) due to signed arithmetic.
This needs to be revisited seperately.
arc:
static inline int test_bit(unsigned int nr, const volatile unsigned long *addr)
^^^^^^^^^^^^
generic:
static inline int test_bit(int nr, const volatile unsigned long *addr)
^^^
Link: https://lore.kernel.org/r/20180830135749.GA13005@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[vgupta: wrote patch based on Will's poc, analysed codegen diffs]
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
|
| H A D | bitops.h | diff cea43147905f1c2b7b48104a5304cf5229f45bec Tue Sep 04 18:11:29 CDT 2018 Vineet Gupta <vgupta@kernel.org> ARC: switch to generic bitops
- !LLSC now only needs a single spinlock for atomics and bitops
- Some codegen changes (slight bloat) with generic bitops
1. code increase due to LD-check-atomic paradigm vs. unconditonal
atomic (but dirty'ing the cache line even if set already).
So despite increase, generic is right thing to do.
2. code decrease (but use of costlier instructions such as DIV vs.
shifts based math) due to signed arithmetic.
This needs to be revisited seperately.
arc:
static inline int test_bit(unsigned int nr, const volatile unsigned long *addr)
^^^^^^^^^^^^
generic:
static inline int test_bit(int nr, const volatile unsigned long *addr)
^^^
Link: https://lore.kernel.org/r/20180830135749.GA13005@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[vgupta: wrote patch based on Will's poc, analysed codegen diffs]
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
|
| /openbmc/linux/arch/arc/kernel/ |
| H A D | smp.c | diff cea43147905f1c2b7b48104a5304cf5229f45bec Tue Sep 04 18:11:29 CDT 2018 Vineet Gupta <vgupta@kernel.org> ARC: switch to generic bitops
- !LLSC now only needs a single spinlock for atomics and bitops
- Some codegen changes (slight bloat) with generic bitops
1. code increase due to LD-check-atomic paradigm vs. unconditonal
atomic (but dirty'ing the cache line even if set already).
So despite increase, generic is right thing to do.
2. code decrease (but use of costlier instructions such as DIV vs.
shifts based math) due to signed arithmetic.
This needs to be revisited seperately.
arc:
static inline int test_bit(unsigned int nr, const volatile unsigned long *addr)
^^^^^^^^^^^^
generic:
static inline int test_bit(int nr, const volatile unsigned long *addr)
^^^
Link: https://lore.kernel.org/r/20180830135749.GA13005@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[vgupta: wrote patch based on Will's poc, analysed codegen diffs]
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
|