Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753519Ab3IKNNk (ORCPT ); Wed, 11 Sep 2013 09:13:40 -0400 Received: from merlin.infradead.org ([205.233.59.134]:44948 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752813Ab3IKNNi (ORCPT ); Wed, 11 Sep 2013 09:13:38 -0400 Date: Wed, 11 Sep 2013 15:13:23 +0200 From: Peter Zijlstra To: Linus Torvalds Cc: Ingo Molnar , Andi Kleen , Peter Anvin , Mike Galbraith , Thomas Gleixner , Arjan van de Ven , Frederic Weisbecker , Linux Kernel Mailing List , "linux-arch@vger.kernel.org" Subject: Re: [PATCH 0/7] preempt_count rework -v2 Message-ID: <20130911131323.GQ31370@twins.programming.kicks-ass.net> References: <20130910130811.507933095@infradead.org> <20130910135152.GD7537@gmail.com> <20130910135636.GA8268@gmail.com> <20130910164519.GL31370@twins.programming.kicks-ass.net> <20130910212509.GA18147@laptop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9022 Lines: 329 On Tue, Sep 10, 2013 at 02:43:06PM -0700, Linus Torvalds wrote: > That said, looking at your patch, I get the *very* strong feeling that > we could make a macro that does all the repetitions for us, and then > have a > > GENERATE_RMW(atomic_sub_and_test, LOCK_PREFIX "subl", "e", "") The below seems to compile.. --- arch/x86/include/asm/atomic.h | 29 +-------- arch/x86/include/asm/atomic64_64.h | 28 +-------- arch/x86/include/asm/local.h | 28 +-------- arch/x86/include/asm/addcc.h | 115 +++++++++++++++++++++++++++++++++++++ 4 files changed, 128 insertions(+), 72 deletions(-) Index: linux-2.6/arch/x86/include/asm/atomic.h =================================================================== --- linux-2.6.orig/arch/x86/include/asm/atomic.h +++ linux-2.6/arch/x86/include/asm/atomic.h @@ -6,6 +6,7 @@ #include #include #include +#include /* * Atomic operations that C can't guarantee us. Useful for @@ -76,12 +77,7 @@ static inline void atomic_sub(int i, ato */ static inline int atomic_sub_and_test(int i, atomic_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "subl %2,%0; sete %1" - : "+m" (v->counter), "=qm" (c) - : "ir" (i) : "memory"); - return c; + GENERATE_ADDcc(v->counter, -i, LOCK_PREFIX, "e"); } /** @@ -118,12 +114,7 @@ static inline void atomic_dec(atomic_t * */ static inline int atomic_dec_and_test(atomic_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "decl %0; sete %1" - : "+m" (v->counter), "=qm" (c) - : : "memory"); - return c != 0; + GENERATE_ADDcc(v->counter, -1, LOCK_PREFIX, "e"); } /** @@ -136,12 +127,7 @@ static inline int atomic_dec_and_test(at */ static inline int atomic_inc_and_test(atomic_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "incl %0; sete %1" - : "+m" (v->counter), "=qm" (c) - : : "memory"); - return c != 0; + GENERATE_ADDcc(v->counter, 1, LOCK_PREFIX, "e"); } /** @@ -155,12 +141,7 @@ static inline int atomic_inc_and_test(at */ static inline int atomic_add_negative(int i, atomic_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "addl %2,%0; sets %1" - : "+m" (v->counter), "=qm" (c) - : "ir" (i) : "memory"); - return c; + GENERATE_ADDcc(v->counter, i, LOCK_PREFIX, "s"); } /** Index: linux-2.6/arch/x86/include/asm/atomic64_64.h =================================================================== --- linux-2.6.orig/arch/x86/include/asm/atomic64_64.h +++ linux-2.6/arch/x86/include/asm/atomic64_64.h @@ -72,12 +72,7 @@ static inline void atomic64_sub(long i, */ static inline int atomic64_sub_and_test(long i, atomic64_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "subq %2,%0; sete %1" - : "=m" (v->counter), "=qm" (c) - : "er" (i), "m" (v->counter) : "memory"); - return c; + GENERATE_ADDcc(v->counter, -i, LOCK_PREFIX, "e"); } /** @@ -116,12 +111,7 @@ static inline void atomic64_dec(atomic64 */ static inline int atomic64_dec_and_test(atomic64_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "decq %0; sete %1" - : "=m" (v->counter), "=qm" (c) - : "m" (v->counter) : "memory"); - return c != 0; + GENERATE_ADDcc(v->counter, -1, LOCK_PREFIX, "e"); } /** @@ -134,12 +124,7 @@ static inline int atomic64_dec_and_test( */ static inline int atomic64_inc_and_test(atomic64_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "incq %0; sete %1" - : "=m" (v->counter), "=qm" (c) - : "m" (v->counter) : "memory"); - return c != 0; + GENERATE_ADDcc(v->counter, 1, LOCK_PREFIX, "e"); } /** @@ -153,12 +138,7 @@ static inline int atomic64_inc_and_test( */ static inline int atomic64_add_negative(long i, atomic64_t *v) { - unsigned char c; - - asm volatile(LOCK_PREFIX "addq %2,%0; sets %1" - : "=m" (v->counter), "=qm" (c) - : "er" (i), "m" (v->counter) : "memory"); - return c; + GENERATE_ADDcc(v->counter, i, LOCK_PREFIX, "s"); } /** Index: linux-2.6/arch/x86/include/asm/local.h =================================================================== --- linux-2.6.orig/arch/x86/include/asm/local.h +++ linux-2.6/arch/x86/include/asm/local.h @@ -52,12 +52,7 @@ static inline void local_sub(long i, loc */ static inline int local_sub_and_test(long i, local_t *l) { - unsigned char c; - - asm volatile(_ASM_SUB "%2,%0; sete %1" - : "+m" (l->a.counter), "=qm" (c) - : "ir" (i) : "memory"); - return c; + GENERATE_ADDcc(l->a.counter, -i, "", "e"); } /** @@ -70,12 +65,7 @@ static inline int local_sub_and_test(lon */ static inline int local_dec_and_test(local_t *l) { - unsigned char c; - - asm volatile(_ASM_DEC "%0; sete %1" - : "+m" (l->a.counter), "=qm" (c) - : : "memory"); - return c != 0; + GENERATE_ADDcc(l->a.counter, -1, "", "e"); } /** @@ -88,12 +78,7 @@ static inline int local_dec_and_test(loc */ static inline int local_inc_and_test(local_t *l) { - unsigned char c; - - asm volatile(_ASM_INC "%0; sete %1" - : "+m" (l->a.counter), "=qm" (c) - : : "memory"); - return c != 0; + GENERATE_ADDcc(l->a.counter, 1, "", "e"); } /** @@ -107,12 +92,7 @@ static inline int local_inc_and_test(loc */ static inline int local_add_negative(long i, local_t *l) { - unsigned char c; - - asm volatile(_ASM_ADD "%2,%0; sets %1" - : "+m" (l->a.counter), "=qm" (c) - : "ir" (i) : "memory"); - return c; + GENERATE_ADDcc(l->a.counter, i, "", "s"); } /** Index: linux-2.6/arch/x86/include/asm/addcc.h =================================================================== --- /dev/null +++ linux-2.6/arch/x86/include/asm/addcc.h @@ -0,0 +1,115 @@ +#ifndef _ASM_X86_ADDcc +#define _ASM_X86_ADDcc + +extern void __bad_addcc_size(void); + +#ifdef CC_HAVE_ASM_GOTO + +#define GENERATE_ADDcc(var, val, lock, cc) \ +do { \ + const int add_ID__ = (__builtin_constant_p(val) && \ + ((val) == 1 || (val) == -1)) ? (val) : 0; \ + \ + switch (sizeof(var)) { \ + case 4: \ + if (add_ID__ == 1) { \ + asm volatile goto(lock "incl %0;" \ + "j" cc " %l[cc_label]" \ + : : "m" (var) \ + : "memory" : cc_label); \ + } else if (add_ID__ == -1) { \ + asm volatile goto(lock "decl %0;" \ + "j" cc " %l[cc_label]" \ + : : "m" (var) \ + : "memory" : cc_label); \ + } else { \ + asm volatile goto(lock "addl %1, %0;" \ + "j" cc " %l[cc_label]" \ + : : "m" (var), "er" (val) \ + : "memory" : cc_label); \ + } \ + break; \ + \ + case 8: \ + if (add_ID__ == 1) { \ + asm volatile goto(lock "incq %0;" \ + "j" cc " %l[cc_label]" \ + : : "m" (var) \ + : "memory" : cc_label); \ + } else if (add_ID__ == -1) { \ + asm volatile goto(lock "decq %0;" \ + "j" cc " %l[cc_label]" \ + : : "m" (var) \ + : "memory" : cc_label); \ + } else { \ + asm volatile goto(lock "addq %1, %0;" \ + "j" cc " %l[cc_label]" \ + : : "m" (var), "er" (val) \ + : "memory" : cc_label); \ + } \ + break; \ + \ + default: __bad_addcc_size(); \ + } \ + \ + return 0; \ +cc_label: \ + return 1; \ +} while (0) + +#else /* !CC_HAVE_ASM_GOTO */ + +#define GENERATE_ADDcc(var, val, lock, cc) \ +do { \ + const int add_ID__ = (__builtin_constant_p(val) && \ + ((val) == 1 || (val) == -1)) ? (val) : 0; \ + char c; \ + \ + switch (sizeof(var)) { \ + case 4: \ + if (add_ID__ == 1) { \ + asm volatile (lock "incl %0;" \ + "set" cc " %1" \ + : "+m" (var), "=qm" (c) \ + : : "memory"); \ + } else if (add_ID__ == -1) { \ + asm volatile (lock "decl %0;" \ + "set" cc " %1" \ + : "+m" (var), "=qm" (c) \ + : : "memory"); \ + } else { \ + asm volatile (lock "addl %2, %0;" \ + "set" cc " %1" \ + : "+m" (var), "=qm" (c) \ + : "er" (val) : "memory"); \ + } \ + break; \ + \ + case 8: \ + if (add_ID__ == 1) { \ + asm volatile (lock "incq %0;" \ + "set" cc " %1" \ + : "+m" (var), "=qm" (c) \ + : : "memory"); \ + } else if (add_ID__ == -1) { \ + asm volatile (lock "decq %0;" \ + "set" cc " %1" \ + : "+m" (var), "=qm" (c) \ + : : "memory"); \ + } else { \ + asm volatile (lock "addq %2, %0;" \ + "set" cc " %1" \ + : "+m" (var), "=qm" (c) \ + : "er" (val) : "memory"); \ + } \ + break; \ + \ + default: __bad_addcc_size(); \ + } \ + \ + return c != 0; \ +} while (0) + +#endif /* CC_HAVE_ASM_GOTO */ + +#endif /* _ASM_X86_ADDcc */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/