From: Nicholas Piggin <npiggin@gmail.com>
To: unlisted-recipients:; (no To-header on input)
Cc: Nicholas Piggin <npiggin@gmail.com>,
Will Deacon <will@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Boqun Feng <boqun.feng@gmail.com>, Ingo Molnar <mingo@redhat.com>,
Waiman Long <longman@redhat.com>,
Anton Blanchard <anton@ozlabs.org>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
kvm-ppc@vger.kernel.org, linux-arch@vger.kernel.org
Subject: [PATCH 2/8] powerpc/pseries: use smp_rmb() in H_CONFER spin yield
Date: Thu, 2 Jul 2020 17:48:33 +1000 [thread overview]
Message-ID: <20200702074839.1057733-3-npiggin@gmail.com> (raw)
In-Reply-To: <20200702074839.1057733-1-npiggin@gmail.com>
There is no need for rmb(), this allows faster lwsync here.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/lib/locks.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/lib/locks.c b/arch/powerpc/lib/locks.c
index 6440d5943c00..47a530de733e 100644
--- a/arch/powerpc/lib/locks.c
+++ b/arch/powerpc/lib/locks.c
@@ -30,7 +30,7 @@ void splpar_spin_yield(arch_spinlock_t *lock)
yield_count = be32_to_cpu(lppaca_of(holder_cpu).yield_count);
if ((yield_count & 1) == 0)
return; /* virtual cpu is currently running */
- rmb();
+ smp_rmb();
if (lock->slock != lock_value)
return; /* something has changed */
plpar_hcall_norets(H_CONFER,
@@ -56,7 +56,7 @@ void splpar_rw_yield(arch_rwlock_t *rw)
yield_count = be32_to_cpu(lppaca_of(holder_cpu).yield_count);
if ((yield_count & 1) == 0)
return; /* virtual cpu is currently running */
- rmb();
+ smp_rmb();
if (rw->lock != lock_value)
return; /* something has changed */
plpar_hcall_norets(H_CONFER,
--
2.23.0
next prev parent reply other threads:[~2020-07-02 7:49 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-02 7:48 [PATCH 0/8] powerpc: queued spinlocks and rwlocks Nicholas Piggin
2020-07-02 7:48 ` [PATCH 1/8] powerpc/powernv: must include hvcall.h to get PAPR defines Nicholas Piggin
2020-07-02 7:48 ` Nicholas Piggin [this message]
2020-07-02 8:28 ` [PATCH 2/8] powerpc/pseries: use smp_rmb() in H_CONFER spin yield Peter Zijlstra
2020-07-02 10:36 ` Nicholas Piggin
2020-07-02 7:48 ` [PATCH 3/8] powerpc/pseries: move some PAPR paravirt functions to their own file Nicholas Piggin
2020-07-02 7:48 ` [PATCH 4/8] powerpc: move spinlock implementation to simple_spinlock Nicholas Piggin
2020-07-02 7:48 ` [PATCH 5/8] powerpc/64s: implement queued spinlocks and rwlocks Nicholas Piggin
2020-07-02 8:02 ` Will Deacon
2020-07-02 10:25 ` Nicholas Piggin
2020-07-02 10:35 ` Will Deacon
2020-07-02 10:47 ` Nicholas Piggin
2020-07-02 10:48 ` Will Deacon
2020-07-03 10:52 ` Michael Ellerman
2020-07-02 7:48 ` [PATCH 6/8] powerpc/pseries: implement paravirt qspinlocks for SPLPAR Nicholas Piggin
2020-07-02 16:15 ` kernel test robot
2020-07-03 0:36 ` Waiman Long
2020-07-02 21:01 ` Waiman Long
2020-07-02 7:48 ` [PATCH 7/8] powerpc/qspinlock: optimised atomic_try_cmpxchg_lock that adds the lock hint Nicholas Piggin
2020-07-02 7:48 ` [PATCH 8/8] powerpc/64s: remove paravirt from simple spinlocks (RFC only) Nicholas Piggin
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