From: Alex Kogan <alex.kogan@oracle.com> To: linux@armlinux.org.uk, peterz@infradead.org, mingo@redhat.com, will.deacon@arm.com, arnd@arndb.de, longman@redhat.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, bp@alien8.de, hpa@zytor.com, x86@kernel.org, guohanjun@huawei.com, jglauber@marvell.com Cc: steven.sistare@oracle.com, daniel.m.jordan@oracle.com, alex.kogan@oracle.com, dave.dice@oracle.com Subject: [PATCH v12 1/5] locking/qspinlock: Rename mcs lock/unlock macros and make them more generic Date: Tue, 17 Nov 2020 18:13:19 -0500 [thread overview] Message-ID: <20201117231323.797104-2-alex.kogan@oracle.com> (raw) In-Reply-To: <20201117231323.797104-1-alex.kogan@oracle.com> The mcs unlock macro (arch_mcs_lock_handoff) should accept the value to be stored into the lock argument as another argument. This allows using the same macro in cases where the value to be stored when passing the lock is different from 1. Signed-off-by: Alex Kogan <alex.kogan@oracle.com> Reviewed-by: Steve Sistare <steven.sistare@oracle.com> Reviewed-by: Waiman Long <longman@redhat.com> --- arch/arm/include/asm/mcs_spinlock.h | 6 +++--- include/asm-generic/mcs_spinlock.h | 4 ++-- kernel/locking/mcs_spinlock.h | 18 +++++++++--------- kernel/locking/qspinlock.c | 4 ++-- kernel/locking/qspinlock_paravirt.h | 2 +- 5 files changed, 17 insertions(+), 17 deletions(-) diff --git a/arch/arm/include/asm/mcs_spinlock.h b/arch/arm/include/asm/mcs_spinlock.h index 529d2cf..1eb4d73 100644 --- a/arch/arm/include/asm/mcs_spinlock.h +++ b/arch/arm/include/asm/mcs_spinlock.h @@ -6,7 +6,7 @@ #include <asm/spinlock.h> /* MCS spin-locking. */ -#define arch_mcs_spin_lock_contended(lock) \ +#define arch_mcs_spin_wait(lock) \ do { \ /* Ensure prior stores are observed before we enter wfe. */ \ smp_mb(); \ @@ -14,9 +14,9 @@ do { \ wfe(); \ } while (0) \ -#define arch_mcs_spin_unlock_contended(lock) \ +#define arch_mcs_lock_handoff(lock, val) \ do { \ - smp_store_release(lock, 1); \ + smp_store_release((lock), (val)); \ dsb_sev(); \ } while (0) diff --git a/include/asm-generic/mcs_spinlock.h b/include/asm-generic/mcs_spinlock.h index 10cd4ff..f933d99 100644 --- a/include/asm-generic/mcs_spinlock.h +++ b/include/asm-generic/mcs_spinlock.h @@ -4,8 +4,8 @@ /* * Architectures can define their own: * - * arch_mcs_spin_lock_contended(l) - * arch_mcs_spin_unlock_contended(l) + * arch_mcs_spin_wait(l) + * arch_mcs_lock_handoff(l, val) * * See kernel/locking/mcs_spinlock.c. */ diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h index 5e10153..904ba5d 100644 --- a/kernel/locking/mcs_spinlock.h +++ b/kernel/locking/mcs_spinlock.h @@ -21,7 +21,7 @@ struct mcs_spinlock { int count; /* nesting count, see qspinlock.c */ }; -#ifndef arch_mcs_spin_lock_contended +#ifndef arch_mcs_spin_wait /* * Using smp_cond_load_acquire() provides the acquire semantics * required so that subsequent operations happen after the @@ -29,20 +29,20 @@ struct mcs_spinlock { * ARM64 would like to do spin-waiting instead of purely * spinning, and smp_cond_load_acquire() provides that behavior. */ -#define arch_mcs_spin_lock_contended(l) \ -do { \ - smp_cond_load_acquire(l, VAL); \ +#define arch_mcs_spin_wait(l) \ +do { \ + smp_cond_load_acquire(l, VAL); \ } while (0) #endif -#ifndef arch_mcs_spin_unlock_contended +#ifndef arch_mcs_lock_handoff /* * smp_store_release() provides a memory barrier to ensure all * operations in the critical section has been completed before * unlocking. */ -#define arch_mcs_spin_unlock_contended(l) \ - smp_store_release((l), 1) +#define arch_mcs_lock_handoff(l, val) \ + smp_store_release((l), (val)) #endif /* @@ -91,7 +91,7 @@ void mcs_spin_lock(struct mcs_spinlock **lock, struct mcs_spinlock *node) WRITE_ONCE(prev->next, node); /* Wait until the lock holder passes the lock down. */ - arch_mcs_spin_lock_contended(&node->locked); + arch_mcs_spin_wait(&node->locked); } /* @@ -115,7 +115,7 @@ void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node) } /* Pass lock to next waiter. */ - arch_mcs_spin_unlock_contended(&next->locked); + arch_mcs_lock_handoff(&next->locked, 1); } #endif /* __LINUX_MCS_SPINLOCK_H */ diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c index cbff6ba..435d696 100644 --- a/kernel/locking/qspinlock.c +++ b/kernel/locking/qspinlock.c @@ -471,7 +471,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) WRITE_ONCE(prev->next, node); pv_wait_node(node, prev); - arch_mcs_spin_lock_contended(&node->locked); + arch_mcs_spin_wait(&node->locked); /* * While waiting for the MCS lock, the next pointer may have @@ -550,7 +550,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) if (!next) next = smp_cond_load_relaxed(&node->next, (VAL)); - arch_mcs_spin_unlock_contended(&next->locked); + arch_mcs_lock_handoff(&next->locked, 1); pv_kick_node(lock, next); release: diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index e84d21a..619d80f 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -368,7 +368,7 @@ static void pv_kick_node(struct qspinlock *lock, struct mcs_spinlock *node) * * Matches with smp_store_mb() and cmpxchg() in pv_wait_node() * - * The write to next->locked in arch_mcs_spin_unlock_contended() + * The write to next->locked in arch_mcs_lock_handoff() * must be ordered before the read of pn->state in the cmpxchg() * below for the code to work correctly. To guarantee full ordering * irrespective of the success or failure of the cmpxchg(), -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Alex Kogan <alex.kogan@oracle.com> To: linux@armlinux.org.uk, peterz@infradead.org, mingo@redhat.com, will.deacon@arm.com, arnd@arndb.de, longman@redhat.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, bp@alien8.de, hpa@zytor.com, x86@kernel.org, guohanjun@huawei.com, jglauber@marvell.com Cc: alex.kogan@oracle.com, dave.dice@oracle.com, steven.sistare@oracle.com, daniel.m.jordan@oracle.com Subject: [PATCH v12 1/5] locking/qspinlock: Rename mcs lock/unlock macros and make them more generic Date: Tue, 17 Nov 2020 18:13:19 -0500 [thread overview] Message-ID: <20201117231323.797104-2-alex.kogan@oracle.com> (raw) In-Reply-To: <20201117231323.797104-1-alex.kogan@oracle.com> The mcs unlock macro (arch_mcs_lock_handoff) should accept the value to be stored into the lock argument as another argument. This allows using the same macro in cases where the value to be stored when passing the lock is different from 1. Signed-off-by: Alex Kogan <alex.kogan@oracle.com> Reviewed-by: Steve Sistare <steven.sistare@oracle.com> Reviewed-by: Waiman Long <longman@redhat.com> --- arch/arm/include/asm/mcs_spinlock.h | 6 +++--- include/asm-generic/mcs_spinlock.h | 4 ++-- kernel/locking/mcs_spinlock.h | 18 +++++++++--------- kernel/locking/qspinlock.c | 4 ++-- kernel/locking/qspinlock_paravirt.h | 2 +- 5 files changed, 17 insertions(+), 17 deletions(-) diff --git a/arch/arm/include/asm/mcs_spinlock.h b/arch/arm/include/asm/mcs_spinlock.h index 529d2cf..1eb4d73 100644 --- a/arch/arm/include/asm/mcs_spinlock.h +++ b/arch/arm/include/asm/mcs_spinlock.h @@ -6,7 +6,7 @@ #include <asm/spinlock.h> /* MCS spin-locking. */ -#define arch_mcs_spin_lock_contended(lock) \ +#define arch_mcs_spin_wait(lock) \ do { \ /* Ensure prior stores are observed before we enter wfe. */ \ smp_mb(); \ @@ -14,9 +14,9 @@ do { \ wfe(); \ } while (0) \ -#define arch_mcs_spin_unlock_contended(lock) \ +#define arch_mcs_lock_handoff(lock, val) \ do { \ - smp_store_release(lock, 1); \ + smp_store_release((lock), (val)); \ dsb_sev(); \ } while (0) diff --git a/include/asm-generic/mcs_spinlock.h b/include/asm-generic/mcs_spinlock.h index 10cd4ff..f933d99 100644 --- a/include/asm-generic/mcs_spinlock.h +++ b/include/asm-generic/mcs_spinlock.h @@ -4,8 +4,8 @@ /* * Architectures can define their own: * - * arch_mcs_spin_lock_contended(l) - * arch_mcs_spin_unlock_contended(l) + * arch_mcs_spin_wait(l) + * arch_mcs_lock_handoff(l, val) * * See kernel/locking/mcs_spinlock.c. */ diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h index 5e10153..904ba5d 100644 --- a/kernel/locking/mcs_spinlock.h +++ b/kernel/locking/mcs_spinlock.h @@ -21,7 +21,7 @@ struct mcs_spinlock { int count; /* nesting count, see qspinlock.c */ }; -#ifndef arch_mcs_spin_lock_contended +#ifndef arch_mcs_spin_wait /* * Using smp_cond_load_acquire() provides the acquire semantics * required so that subsequent operations happen after the @@ -29,20 +29,20 @@ struct mcs_spinlock { * ARM64 would like to do spin-waiting instead of purely * spinning, and smp_cond_load_acquire() provides that behavior. */ -#define arch_mcs_spin_lock_contended(l) \ -do { \ - smp_cond_load_acquire(l, VAL); \ +#define arch_mcs_spin_wait(l) \ +do { \ + smp_cond_load_acquire(l, VAL); \ } while (0) #endif -#ifndef arch_mcs_spin_unlock_contended +#ifndef arch_mcs_lock_handoff /* * smp_store_release() provides a memory barrier to ensure all * operations in the critical section has been completed before * unlocking. */ -#define arch_mcs_spin_unlock_contended(l) \ - smp_store_release((l), 1) +#define arch_mcs_lock_handoff(l, val) \ + smp_store_release((l), (val)) #endif /* @@ -91,7 +91,7 @@ void mcs_spin_lock(struct mcs_spinlock **lock, struct mcs_spinlock *node) WRITE_ONCE(prev->next, node); /* Wait until the lock holder passes the lock down. */ - arch_mcs_spin_lock_contended(&node->locked); + arch_mcs_spin_wait(&node->locked); } /* @@ -115,7 +115,7 @@ void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node) } /* Pass lock to next waiter. */ - arch_mcs_spin_unlock_contended(&next->locked); + arch_mcs_lock_handoff(&next->locked, 1); } #endif /* __LINUX_MCS_SPINLOCK_H */ diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c index cbff6ba..435d696 100644 --- a/kernel/locking/qspinlock.c +++ b/kernel/locking/qspinlock.c @@ -471,7 +471,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) WRITE_ONCE(prev->next, node); pv_wait_node(node, prev); - arch_mcs_spin_lock_contended(&node->locked); + arch_mcs_spin_wait(&node->locked); /* * While waiting for the MCS lock, the next pointer may have @@ -550,7 +550,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) if (!next) next = smp_cond_load_relaxed(&node->next, (VAL)); - arch_mcs_spin_unlock_contended(&next->locked); + arch_mcs_lock_handoff(&next->locked, 1); pv_kick_node(lock, next); release: diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index e84d21a..619d80f 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -368,7 +368,7 @@ static void pv_kick_node(struct qspinlock *lock, struct mcs_spinlock *node) * * Matches with smp_store_mb() and cmpxchg() in pv_wait_node() * - * The write to next->locked in arch_mcs_spin_unlock_contended() + * The write to next->locked in arch_mcs_lock_handoff() * must be ordered before the read of pn->state in the cmpxchg() * below for the code to work correctly. To guarantee full ordering * irrespective of the success or failure of the cmpxchg(), -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-11-17 23:14 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-11-17 23:13 [PATCH v12 0/5] Add NUMA-awareness to qspinlock Alex Kogan 2020-11-17 23:13 ` Alex Kogan 2020-11-17 23:13 ` Alex Kogan [this message] 2020-11-17 23:13 ` [PATCH v12 1/5] locking/qspinlock: Rename mcs lock/unlock macros and make them more generic Alex Kogan 2020-11-17 23:13 ` [PATCH v12 2/5] locking/qspinlock: Refactor the qspinlock slow path Alex Kogan 2020-11-17 23:13 ` Alex Kogan 2020-11-17 23:13 ` [PATCH v12 3/5] locking/qspinlock: Introduce CNA into the slow path of qspinlock Alex Kogan 2020-11-17 23:13 ` Alex Kogan 2020-11-22 7:38 ` [locking/qspinlock] 0dd6d5b8c0: vm-scalability.throughput 102.9% improvement kernel test robot 2020-11-17 23:13 ` [PATCH v12 4/5] locking/qspinlock: Introduce starvation avoidance into CNA Alex Kogan 2020-11-17 23:13 ` Alex Kogan 2020-11-17 23:13 ` [PATCH v12 5/5] locking/qspinlock: Avoid moving certain threads between waiting queues in CNA Alex Kogan 2020-11-17 23:13 ` Alex Kogan 2020-11-22 9:47 ` [locking/qspinlock] 6f9a39a437: unixbench.score -17.3% regression kernel test robot
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