From: Boqun Feng <boqun.feng@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>, Will Deacon <will@kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org, bigeasy@linutronix.de,
juri.lelli@redhat.com, williams@redhat.com, bristot@redhat.com,
longman@redhat.com, dave@stgolabs.net, jack@suse.com
Subject: Re: [PATCH] locking/percpu_rwsem: Rewrite to not use rwsem
Date: Mon, 5 Aug 2019 22:43:18 +0800 [thread overview]
Message-ID: <20190805144318.GA972@tardis> (raw)
In-Reply-To: <20190805140241.GI2332@hirez.programming.kicks-ass.net>
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On Mon, Aug 05, 2019 at 04:02:41PM +0200, Peter Zijlstra wrote:
[...]
>
> static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
> {
> + rwsem_release(&sem->dep_map, 1, _RET_IP_);
> +
> preempt_disable();
> /*
> * Same as in percpu_down_read().
> */
> - if (likely(rcu_sync_is_idle(&sem->rss)))
> + if (likely(rcu_sync_is_idle(&sem->rss))) {
> __this_cpu_dec(*sem->read_count);
> - else
> - __percpu_up_read(sem); /* Unconditional memory barrier */
> - preempt_enable();
> + preempt_enable();
> + return;
> + }
>
> - rwsem_release(&sem->rw_sem.dep_map, 1, _RET_IP_);
Missing a preempt_enable() here?
Regards,
Boqun
> + __percpu_up_read(sem); /* Unconditional memory barrier */
> }
>
[...]
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next prev parent reply other threads:[~2019-08-05 14:43 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-05 14:02 [PATCH] locking/percpu_rwsem: Rewrite to not use rwsem Peter Zijlstra
2019-08-05 14:43 ` Boqun Feng [this message]
2019-08-05 14:58 ` Boqun Feng
2019-08-05 15:43 ` Peter Zijlstra
2019-08-06 14:15 ` Boqun Feng
2019-08-06 16:17 ` Oleg Nesterov
2019-08-06 17:15 ` Peter Zijlstra
2019-08-07 9:56 ` Oleg Nesterov
2019-10-29 18:47 ` Peter Zijlstra
2019-10-30 14:21 ` Oleg Nesterov
2019-10-30 16:09 ` Peter Zijlstra
2019-10-30 17:52 ` Peter Zijlstra
2019-10-30 18:47 ` Peter Zijlstra
2019-10-30 19:31 ` Peter Zijlstra
2019-10-31 6:11 ` Peter Zijlstra
2019-08-07 14:45 ` Will Deacon
2019-10-29 19:06 ` Peter Zijlstra
2019-10-30 15:57 ` Oleg Nesterov
2019-10-30 16:47 ` Peter Zijlstra
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