From: Eric Dumazet <eric.dumazet@gmail•com>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl•ca>
Cc: Jiri Olsa <jolsa@redhat•com>, Ingo Molnar <mingo@elte•hu>,
Peter Zijlstra <a.p.zijlstra@chello•nl>,
netdev@vger•kernel.org, linux-kernel@vger•kernel.org,
fbl@redhat•com, nhorman@redhat•com, davem@redhat•com,
htejun@gmail•com, jarkao2@gmail•com, oleg@redhat•com,
davidel@xmailserver•org
Subject: Re: [PATCHv5 2/2] memory barrier: adding smp_mb__after_lock
Date: Tue, 07 Jul 2009 17:23:18 +0200 [thread overview]
Message-ID: <4A536866.1050906@gmail.com> (raw)
In-Reply-To: <20090707145710.GB7124@Krystal>
Mathieu Desnoyers a écrit :
> But read_lock + smp_mb__after_lock + read_unlock is not well suited for
> powerpc, arm, mips and probably others where there is an explicit memory
> barrier at the end of the read lock primitive.
>
> One thing that would be efficient for all architectures is to create a
> locking primitive that contains the smp_mb, e.g.:
>
> read_lock_smp_mb()
>
> which would act as a read_lock which does a full smp_mb after the lock
> is taken.
>
> The naming may be a bit odd, better ideas are welcome.
I see your point now, thanks for your patience.
Jiri, I think your first patch can be applied (including the full smp_mb()),
then we will optimize both for x86 and other arches, when all
arch maintainers have a chance to change
"read_lock();smp_mb()" to a faster "read_lock_mb()" or something :)
next prev parent reply other threads:[~2009-07-07 15:23 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-03 8:12 [PATCHv5 0/2] net: fix race in the receive/select Jiri Olsa
2009-07-03 8:13 ` [PATCHv5 1/2] net: adding memory barrier to the poll and receive callbacks Jiri Olsa
2009-07-07 15:56 ` Eric Dumazet
2009-07-03 8:14 ` [PATCHv5 2/2] memory barrier: adding smp_mb__after_lock Jiri Olsa
2009-07-03 9:06 ` Ingo Molnar
2009-07-03 9:20 ` Eric Dumazet
2009-07-03 9:24 ` Ingo Molnar
2009-07-03 9:56 ` Jiri Olsa
2009-07-03 10:25 ` Ingo Molnar
2009-07-03 11:18 ` Jiri Olsa
2009-07-03 11:30 ` Jarek Poplawski
2009-07-03 11:43 ` Jiri Olsa
2009-07-07 10:18 ` Jiri Olsa
2009-07-07 13:46 ` Jiri Olsa
2009-07-07 14:01 ` Mathieu Desnoyers
2009-07-07 14:34 ` Oleg Nesterov
2009-07-07 15:04 ` Mathieu Desnoyers
2009-07-07 15:44 ` Oleg Nesterov
2009-07-07 15:50 ` Peter Zijlstra
2009-07-07 19:45 ` Mathieu Desnoyers
2009-07-07 22:44 ` Eric Dumazet
2009-07-07 23:28 ` Mathieu Desnoyers
2009-07-07 23:51 ` Oleg Nesterov
2009-07-08 4:34 ` Mathieu Desnoyers
2009-07-08 7:18 ` Jarek Poplawski
2009-07-07 14:34 ` Jiri Olsa
2009-07-07 14:42 ` Eric Dumazet
2009-07-07 14:57 ` Mathieu Desnoyers
2009-07-07 15:23 ` Eric Dumazet [this message]
2009-07-08 17:47 ` Jiri Olsa
2009-07-08 18:07 ` David Miller
2009-07-08 18:16 ` Jiri Olsa
2009-07-03 14:04 ` Mathieu Desnoyers
2009-07-03 15:29 ` Herbert Xu
2009-07-03 15:37 ` Eric Dumazet
2009-07-03 15:47 ` Mathieu Desnoyers
2009-07-03 17:06 ` Paul E. McKenney
2009-07-03 17:31 ` Mathieu Desnoyers
2009-07-03 15:40 ` Mathieu Desnoyers
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