Re: [PATCH] block: switch to atomic_t for request references
From: Peter Zijlstra <peterz@infradead.org>
Date: 2021-12-07 17:41:12
Also in:
lkml
On Tue, Dec 07, 2021 at 05:52:13PM +0100, Peter Zijlstra wrote:
quoted hunk ↗ jump to hunk
It's a bit gross, and there seems to be a problem with macro expansion of __ofl, but it 'works'. ---diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h index 5e754e895767..921ecfd5a40b 100644 --- a/arch/x86/include/asm/atomic.h +++ b/arch/x86/include/asm/atomic.h@@ -263,6 +263,22 @@ static __always_inline int arch_atomic_fetch_xor(int i, atomic_t *v) } #define arch_atomic_fetch_xor arch_atomic_fetch_xor +#define atomic_dec_and_test_ofl(_v, __ofl) \ +({ \ + __label__ __zero; \ + __label__ __out; \ + bool __ret = false; \ + asm_volatile_goto (LOCK_PREFIX "decl %[var]\n\t" \ + "jz %l[__zero]\n\t" \ + "jl %l[__ofl]" \
%l2 and it works much better...
+ : : [var] "m" ((_v)->counter) \ + : "memory" \ + : __zero, __ofl); \ + goto __out; \ +__zero: __ret = true; \ +__out: __ret; \ +})