From: Tyler Retzlaff <roretzla@linux.microsoft.com>
To: dev@dpdk.org
Cc: Gaetan Rivet <grive@u256.net>,
Bruce Richardson <bruce.richardson@intel.com>,
Thomas Monjalon <thomas@monjalon.net>,
Nicolas Chautru <nicolas.chautru@intel.com>,
Yipeng Wang <yipeng1.wang@intel.com>,
Sameh Gobriel <sameh.gobriel@intel.com>,
Vladimir Medvedkin <vladimir.medvedkin@intel.com>,
Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>,
Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>,
Anatoly Burakov <anatoly.burakov@intel.com>,
Olivier Matz <olivier.matz@6wind.com>,
Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>,
Joyce Kong <joyce.kong@arm.com>,
Erik Gabriel Carrillo <erik.g.carrillo@intel.com>,
Liang Ma <liangma@liangbit.com>,
Peter Mccarthy <peter.mccarthy@intel.com>,
Jerin Jacob <jerinj@marvell.com>,
Maciej Czekaj <mczekaj@marvell.com>,
David Hunt <david.hunt@intel.com>,
Ruifeng Wang <ruifeng.wang@arm.com>,
Min Zhou <zhoumin@loongson.cn>,
David Christensen <drc@linux.vnet.ibm.com>,
Stanislaw Kardach <kda@semihalf.com>,
david.marchand@redhat.com, stephen@networkplumber.org,
mb@smartsharesystems.com,
Tyler Retzlaff <roretzla@linux.microsoft.com>
Subject: [PATCH v2 4/4] eal: adapt rte spinlock and rwlock APIs to use C11 atomics
Date: Mon, 31 Jul 2023 22:03:54 -0700 [thread overview]
Message-ID: <1690866234-28365-5-git-send-email-roretzla@linux.microsoft.com> (raw)
In-Reply-To: <1690866234-28365-1-git-send-email-roretzla@linux.microsoft.com>
Adapt rte_spinlock.h and rte_rwlock.h APIs to use standard C11 atomics.
Update consumers of the spinlock and rwlock APIs for the API break.
Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
---
lib/eal/include/generic/rte_rwlock.h | 46 ++++++++++++++++++----------------
lib/eal/include/generic/rte_spinlock.h | 21 ++++++++--------
lib/eal/x86/include/rte_spinlock.h | 2 +-
3 files changed, 36 insertions(+), 33 deletions(-)
diff --git a/lib/eal/include/generic/rte_rwlock.h b/lib/eal/include/generic/rte_rwlock.h
index 9e083bb..b659c4c 100644
--- a/lib/eal/include/generic/rte_rwlock.h
+++ b/lib/eal/include/generic/rte_rwlock.h
@@ -22,6 +22,8 @@
* https://locklessinc.com/articles/locks/
*/
+#include <stdatomic.h>
+
#ifdef __cplusplus
extern "C" {
#endif
@@ -57,7 +59,7 @@
#define RTE_RWLOCK_READ 0x4 /* Reader increment */
typedef struct __rte_lockable {
- int32_t cnt;
+ int32_t _Atomic cnt;
} rte_rwlock_t;
/**
@@ -92,21 +94,21 @@
while (1) {
/* Wait while writer is present or pending */
- while (__atomic_load_n(&rwl->cnt, __ATOMIC_RELAXED)
+ while (atomic_load_explicit(&rwl->cnt, memory_order_relaxed)
& RTE_RWLOCK_MASK)
rte_pause();
/* Try to get read lock */
- x = __atomic_fetch_add(&rwl->cnt, RTE_RWLOCK_READ,
- __ATOMIC_ACQUIRE) + RTE_RWLOCK_READ;
+ x = atomic_fetch_add_explicit(&rwl->cnt, RTE_RWLOCK_READ,
+ memory_order_acquire) + RTE_RWLOCK_READ;
/* If no writer, then acquire was successful */
if (likely(!(x & RTE_RWLOCK_MASK)))
return;
/* Lost race with writer, backout the change. */
- __atomic_fetch_sub(&rwl->cnt, RTE_RWLOCK_READ,
- __ATOMIC_RELAXED);
+ atomic_fetch_sub_explicit(&rwl->cnt, RTE_RWLOCK_READ,
+ memory_order_relaxed);
}
}
@@ -127,20 +129,20 @@
{
int32_t x;
- x = __atomic_load_n(&rwl->cnt, __ATOMIC_RELAXED);
+ x = atomic_load_explicit(&rwl->cnt, memory_order_relaxed);
/* fail if write lock is held or writer is pending */
if (x & RTE_RWLOCK_MASK)
return -EBUSY;
/* Try to get read lock */
- x = __atomic_fetch_add(&rwl->cnt, RTE_RWLOCK_READ,
- __ATOMIC_ACQUIRE) + RTE_RWLOCK_READ;
+ x = atomic_fetch_add_explicit(&rwl->cnt, RTE_RWLOCK_READ,
+ memory_order_acquire) + RTE_RWLOCK_READ;
/* Back out if writer raced in */
if (unlikely(x & RTE_RWLOCK_MASK)) {
- __atomic_fetch_sub(&rwl->cnt, RTE_RWLOCK_READ,
- __ATOMIC_RELEASE);
+ atomic_fetch_sub_explicit(&rwl->cnt, RTE_RWLOCK_READ,
+ memory_order_release);
return -EBUSY;
}
@@ -158,7 +160,7 @@
__rte_unlock_function(rwl)
__rte_no_thread_safety_analysis
{
- __atomic_fetch_sub(&rwl->cnt, RTE_RWLOCK_READ, __ATOMIC_RELEASE);
+ atomic_fetch_sub_explicit(&rwl->cnt, RTE_RWLOCK_READ, memory_order_release);
}
/**
@@ -178,10 +180,10 @@
{
int32_t x;
- x = __atomic_load_n(&rwl->cnt, __ATOMIC_RELAXED);
+ x = atomic_load_explicit(&rwl->cnt, memory_order_relaxed);
if (x < RTE_RWLOCK_WRITE &&
- __atomic_compare_exchange_n(&rwl->cnt, &x, x + RTE_RWLOCK_WRITE,
- 1, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED))
+ atomic_compare_exchange_weak_explicit(&rwl->cnt, &x, x + RTE_RWLOCK_WRITE,
+ memory_order_acquire, memory_order_relaxed))
return 0;
else
return -EBUSY;
@@ -201,22 +203,22 @@
int32_t x;
while (1) {
- x = __atomic_load_n(&rwl->cnt, __ATOMIC_RELAXED);
+ x = atomic_load_explicit(&rwl->cnt, memory_order_relaxed);
/* No readers or writers? */
if (likely(x < RTE_RWLOCK_WRITE)) {
/* Turn off RTE_RWLOCK_WAIT, turn on RTE_RWLOCK_WRITE */
- if (__atomic_compare_exchange_n(&rwl->cnt, &x, RTE_RWLOCK_WRITE, 1,
- __ATOMIC_ACQUIRE, __ATOMIC_RELAXED))
+ if (atomic_compare_exchange_weak_explicit(&rwl->cnt, &x, RTE_RWLOCK_WRITE,
+ memory_order_acquire, memory_order_relaxed))
return;
}
/* Turn on writer wait bit */
if (!(x & RTE_RWLOCK_WAIT))
- __atomic_fetch_or(&rwl->cnt, RTE_RWLOCK_WAIT, __ATOMIC_RELAXED);
+ atomic_fetch_or_explicit(&rwl->cnt, RTE_RWLOCK_WAIT, memory_order_relaxed);
/* Wait until no readers before trying again */
- while (__atomic_load_n(&rwl->cnt, __ATOMIC_RELAXED) > RTE_RWLOCK_WAIT)
+ while (atomic_load_explicit(&rwl->cnt, memory_order_relaxed) > RTE_RWLOCK_WAIT)
rte_pause();
}
@@ -233,7 +235,7 @@
__rte_unlock_function(rwl)
__rte_no_thread_safety_analysis
{
- __atomic_fetch_sub(&rwl->cnt, RTE_RWLOCK_WRITE, __ATOMIC_RELEASE);
+ atomic_fetch_sub_explicit(&rwl->cnt, RTE_RWLOCK_WRITE, memory_order_release);
}
/**
@@ -247,7 +249,7 @@
static inline int
rte_rwlock_write_is_locked(rte_rwlock_t *rwl)
{
- if (__atomic_load_n(&rwl->cnt, __ATOMIC_RELAXED) & RTE_RWLOCK_WRITE)
+ if (atomic_load_explicit(&rwl->cnt, memory_order_relaxed) & RTE_RWLOCK_WRITE)
return 1;
return 0;
diff --git a/lib/eal/include/generic/rte_spinlock.h b/lib/eal/include/generic/rte_spinlock.h
index c50ebaa..d92432d 100644
--- a/lib/eal/include/generic/rte_spinlock.h
+++ b/lib/eal/include/generic/rte_spinlock.h
@@ -17,6 +17,8 @@
* All locks must be initialised before use, and only initialised once.
*/
+#include <stdatomic.h>
+
#include <rte_lcore.h>
#ifdef RTE_FORCE_INTRINSICS
#include <rte_common.h>
@@ -28,7 +30,7 @@
* The rte_spinlock_t type.
*/
typedef struct __rte_lockable {
- volatile int locked; /**< lock status 0 = unlocked, 1 = locked */
+ int _Atomic locked; /**< lock status 0 = unlocked, 1 = locked */
} rte_spinlock_t;
/**
@@ -65,10 +67,10 @@
{
int exp = 0;
- while (!__atomic_compare_exchange_n(&sl->locked, &exp, 1, 0,
- __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) {
- rte_wait_until_equal_32((volatile uint32_t *)&sl->locked,
- 0, __ATOMIC_RELAXED);
+ while (!atomic_compare_exchange_strong_explicit(&sl->locked, &exp, 1,
+ memory_order_acquire, memory_order_relaxed)) {
+ rte_wait_until_equal_32((uint32_t _Atomic *)&sl->locked,
+ 0, memory_order_relaxed);
exp = 0;
}
}
@@ -89,7 +91,7 @@
rte_spinlock_unlock(rte_spinlock_t *sl)
__rte_no_thread_safety_analysis
{
- __atomic_store_n(&sl->locked, 0, __ATOMIC_RELEASE);
+ atomic_store_explicit(&sl->locked, 0, memory_order_release);
}
#endif
@@ -112,9 +114,8 @@
__rte_no_thread_safety_analysis
{
int exp = 0;
- return __atomic_compare_exchange_n(&sl->locked, &exp, 1,
- 0, /* disallow spurious failure */
- __ATOMIC_ACQUIRE, __ATOMIC_RELAXED);
+ return atomic_compare_exchange_strong_explicit(&sl->locked, &exp, 1,
+ memory_order_acquire, memory_order_relaxed);
}
#endif
@@ -128,7 +129,7 @@
*/
static inline int rte_spinlock_is_locked (rte_spinlock_t *sl)
{
- return __atomic_load_n(&sl->locked, __ATOMIC_ACQUIRE);
+ return atomic_load_explicit(&sl->locked, memory_order_acquire);
}
/**
diff --git a/lib/eal/x86/include/rte_spinlock.h b/lib/eal/x86/include/rte_spinlock.h
index 0b20ddf..3e7f8ac 100644
--- a/lib/eal/x86/include/rte_spinlock.h
+++ b/lib/eal/x86/include/rte_spinlock.h
@@ -78,7 +78,7 @@ static inline int rte_tm_supported(void)
}
static inline int
-rte_try_tm(volatile int *lock)
+rte_try_tm(int _Atomic *lock)
{
int i, retries;
--
1.8.3.1
next prev parent reply other threads:[~2023-08-01 5:04 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-31 21:07 [PATCH 0/4] eal: update public API to use stdatomic atomics Tyler Retzlaff
2023-07-31 21:07 ` [PATCH 1/4] build: require minimum c11 compiler Tyler Retzlaff
2023-07-31 21:07 ` [PATCH 2/4] devtools: forbid use of GCC atomic builtins Tyler Retzlaff
2023-07-31 21:07 ` [PATCH 3/4] eal: adapt rte pause APIs to use C11 atomics Tyler Retzlaff
2023-07-31 21:07 ` [PATCH 4/4] eal: adapt rte spinlock and rwlock " Tyler Retzlaff
2023-08-01 5:03 ` [PATCH v2 0/4] eal: update public API to use stdatomic atomics Tyler Retzlaff
2023-08-01 5:03 ` [PATCH v2 1/4] build: require minimum c11 compiler Tyler Retzlaff
2023-08-01 5:03 ` [PATCH v2 2/4] devtools: forbid use of GCC atomic builtins Tyler Retzlaff
2023-08-01 5:03 ` [PATCH v2 3/4] eal: adapt rte pause APIs to use C11 atomics Tyler Retzlaff
2023-08-01 5:03 ` Tyler Retzlaff [this message]
2023-08-01 7:33 ` [PATCH v2 0/4] eal: update public API to use stdatomic atomics Morten Brørup
2023-08-01 17:07 ` Tyler Retzlaff
2023-08-02 5:13 ` [PATCH v3 " Tyler Retzlaff
2023-08-02 5:13 ` [PATCH v3 1/4] build: require minimum c11 compiler Tyler Retzlaff
2023-08-02 5:13 ` [PATCH v3 2/4] devtools: forbid use of GCC atomic builtins Tyler Retzlaff
2023-08-02 5:13 ` [PATCH v3 3/4] eal: adapt rte pause APIs to use C11 atomics Tyler Retzlaff
2023-08-02 5:13 ` [PATCH v3 4/4] eal: adapt rte spinlock and rwlock " Tyler Retzlaff
2023-08-02 5:31 ` [PATCH v4 0/4] eal: update public API to use stdatomic atomics Tyler Retzlaff
2023-08-02 5:31 ` [PATCH v4 1/4] build: require minimum c11 compiler Tyler Retzlaff
2023-08-02 5:31 ` [PATCH v4 2/4] devtools: forbid use of GCC atomic builtins Tyler Retzlaff
2023-08-02 5:31 ` [PATCH v4 3/4] eal: adapt rte pause APIs to use C11 atomics Tyler Retzlaff
2023-08-02 5:31 ` [PATCH v4 4/4] eal: adapt rte spinlock and rwlock " Tyler Retzlaff
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