From: Peter Zijlstra <peterz@infradead.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>, Ingo Molnar <mingo@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
"Paul E.McKenney" <paulmck@linux.vnet.ibm.com>,
Waiman Long <Waiman.Long@hp.com>,
linux-kernel@vger.kernel.org
Subject: Re: qrwlock && read-after-read
Date: Tue, 4 Aug 2015 19:32:32 +0200 [thread overview]
Message-ID: <20150804173232.GS25159@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20150804134043.GA24252@redhat.com>
On Tue, Aug 04, 2015 at 03:40:43PM +0200, Oleg Nesterov wrote:
> Lets fix the lockdep annotaions?
>
> Oleg.
>
> --- x/include/linux/rwlock_api_smp.h
> +++ x/include/linux/rwlock_api_smp.h
> @@ -146,7 +146,7 @@ static inline int __raw_write_trylock(rw
> static inline void __raw_read_lock(rwlock_t *lock)
> {
> preempt_disable();
> - rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
> + lock_acquire(..., /* read */ in_interrupt() 2 : 1, ...);
> LOCK_CONTENDED(lock, do_raw_read_trylock, do_raw_read_lock);
> }
I think that suffers the same problems we had before; see:
8acd91e86208 ("locking/lockdep: Revert qrwlock recusive stuff")
next prev parent reply other threads:[~2015-08-04 17:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-04 13:00 Oleg Nesterov
2015-08-04 13:10 ` Peter Zijlstra
2015-08-04 13:40 ` Oleg Nesterov
2015-08-04 17:32 ` Peter Zijlstra [this message]
2015-08-04 13:51 ` Linus Torvalds
2015-08-05 13:08 ` Oleg Nesterov
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