diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2023-09-06 20:58:44 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-09-15 13:16:35 +0200 |
| commit | 54cd971c6f4461fb6b178579751788bf4f64dfca (patch) | |
| tree | 91ae3d369ede37c8e75ede76d54a8d835ff9a2bd /arch/x86 | |
| parent | 3dae5c43badf285e22f6d88388e8a232a83bdfec (diff) | |
x86/percpu: Define {raw,this}_cpu_try_cmpxchg{64,128}
Define target-specific {raw,this}_cpu_try_cmpxchg64() and
{raw,this}_cpu_try_cmpxchg128() macros. These definitions override
the generic fallback definitions and enable target-specific
optimized implementations.
Several places in mm/slub.o improve from e.g.:
53bc: 48 8d 4f 40 lea 0x40(%rdi),%rcx
53c0: 48 89 fa mov %rdi,%rdx
53c3: 49 8b 5c 05 00 mov 0x0(%r13,%rax,1),%rbx
53c8: 4c 89 e8 mov %r13,%rax
53cb: 49 8d 30 lea (%r8),%rsi
53ce: e8 00 00 00 00 call 53d3 <...>
53cf: R_X86_64_PLT32 this_cpu_cmpxchg16b_emu-0x4
53d3: 48 31 d7 xor %rdx,%rdi
53d6: 4c 31 e8 xor %r13,%rax
53d9: 48 09 c7 or %rax,%rdi
53dc: 75 ae jne 538c <...>
to:
53bc: 48 8d 4a 40 lea 0x40(%rdx),%rcx
53c0: 49 8b 1c 07 mov (%r15,%rax,1),%rbx
53c4: 4c 89 f8 mov %r15,%rax
53c7: 48 8d 37 lea (%rdi),%rsi
53ca: e8 00 00 00 00 call 53cf <...>
53cb: R_X86_64_PLT32 this_cpu_cmpxchg16b_emu-0x4
53cf: 75 bb jne 538c <...>
reducing the size of mm/slub.o by 80 bytes:
text data bss dec hex filename
39758 5337 4208 49303 c097 slub-new.o
39838 5337 4208 49383 c0e7 slub-old.o
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230906185941.53527-1-ubizjak@gmail.com
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/percpu.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 34734d730463..4c3641927f39 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -237,12 +237,47 @@ do { \ #define raw_cpu_cmpxchg64(pcp, oval, nval) percpu_cmpxchg64_op(8, , pcp, oval, nval) #define this_cpu_cmpxchg64(pcp, oval, nval) percpu_cmpxchg64_op(8, volatile, pcp, oval, nval) + +#define percpu_try_cmpxchg64_op(size, qual, _var, _ovalp, _nval) \ +({ \ + bool success; \ + u64 *_oval = (u64 *)(_ovalp); \ + union { \ + u64 var; \ + struct { \ + u32 low, high; \ + }; \ + } old__, new__; \ + \ + old__.var = *_oval; \ + new__.var = _nval; \ + \ + asm qual (ALTERNATIVE("leal %P[var], %%esi; call this_cpu_cmpxchg8b_emu", \ + "cmpxchg8b " __percpu_arg([var]), X86_FEATURE_CX8) \ + CC_SET(z) \ + : CC_OUT(z) (success), \ + [var] "+m" (_var), \ + "+a" (old__.low), \ + "+d" (old__.high) \ + : "b" (new__.low), \ + "c" (new__.high) \ + : "memory", "esi"); \ + if (unlikely(!success)) \ + *_oval = old__.var; \ + likely(success); \ +}) + +#define raw_cpu_try_cmpxchg64(pcp, ovalp, nval) percpu_try_cmpxchg64_op(8, , pcp, ovalp, nval) +#define this_cpu_try_cmpxchg64(pcp, ovalp, nval) percpu_try_cmpxchg64_op(8, volatile, pcp, ovalp, nval) #endif #ifdef CONFIG_X86_64 #define raw_cpu_cmpxchg64(pcp, oval, nval) percpu_cmpxchg_op(8, , pcp, oval, nval); #define this_cpu_cmpxchg64(pcp, oval, nval) percpu_cmpxchg_op(8, volatile, pcp, oval, nval); +#define raw_cpu_try_cmpxchg64(pcp, ovalp, nval) percpu_try_cmpxchg_op(8, , pcp, ovalp, nval); +#define this_cpu_try_cmpxchg64(pcp, ovalp, nval) percpu_try_cmpxchg_op(8, volatile, pcp, ovalp, nval); + #define percpu_cmpxchg128_op(size, qual, _var, _oval, _nval) \ ({ \ union { \ @@ -269,6 +304,38 @@ do { \ #define raw_cpu_cmpxchg128(pcp, oval, nval) percpu_cmpxchg128_op(16, , pcp, oval, nval) #define this_cpu_cmpxchg128(pcp, oval, nval) percpu_cmpxchg128_op(16, volatile, pcp, oval, nval) + +#define percpu_try_cmpxchg128_op(size, qual, _var, _ovalp, _nval) \ +({ \ + bool success; \ + u128 *_oval = (u128 *)(_ovalp); \ + union { \ + u128 var; \ + struct { \ + u64 low, high; \ + }; \ + } old__, new__; \ + \ + old__.var = *_oval; \ + new__.var = _nval; \ + \ + asm qual (ALTERNATIVE("leaq %P[var], %%rsi; call this_cpu_cmpxchg16b_emu", \ + "cmpxchg16b " __percpu_arg([var]), X86_FEATURE_CX16) \ + CC_SET(z) \ + : CC_OUT(z) (success), \ + [var] "+m" (_var), \ + "+a" (old__.low), \ + "+d" (old__.high) \ + : "b" (new__.low), \ + "c" (new__.high) \ + : "memory", "rsi"); \ + if (unlikely(!success)) \ + *_oval = old__.var; \ + likely(success); \ +}) + +#define raw_cpu_try_cmpxchg128(pcp, ovalp, nval) percpu_try_cmpxchg128_op(16, , pcp, ovalp, nval) +#define this_cpu_try_cmpxchg128(pcp, ovalp, nval) percpu_try_cmpxchg128_op(16, volatile, pcp, ovalp, nval) #endif /* |