From: Vlad Yasevich <vyasevich@gmail.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
"Michael S. Tsirkin" <mst@redhat.com>
Cc: netdev@vger.kernel.org, David Miller <davem@davemloft.net>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: Re: [PULL 2/2] vhost: replace rcu with mutex
Date: Tue, 03 Jun 2014 09:35:17 -0400 [thread overview]
Message-ID: <538DCF15.4080904@gmail.com> (raw)
In-Reply-To: <538DC422.1050303@redhat.com>
On 06/03/2014 08:48 AM, Paolo Bonzini wrote:
> Il 02/06/2014 23:58, Eric Dumazet ha scritto:
>> This looks dubious
>>
>> What about using kfree_rcu() instead ?
>
> It would lead to unbound allocation from userspace.
>
>> translate_desc() still uses rcu_read_lock(), its not clear if the mutex
>> is really held.
>
> Yes, vhost_get_vq_desc must be called with the vq mutex held.
>
> The rcu_read_lock/unlock in translate_desc is unnecessary.
>
If that's true, then does dev->memory really needs to be rcu protected?
It appears to always be read under mutex.
-vlad
> Paolo
> --
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next prev parent reply other threads:[~2014-06-03 13:35 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-02 21:30 [PULL 0/2] vhost enhancements for 3.16 Michael S. Tsirkin
2014-06-02 21:30 ` [PULL 1/2] vhost-net: extend device allocation to vmalloc Michael S. Tsirkin
2014-06-02 21:30 ` [PULL 2/2] vhost: replace rcu with mutex Michael S. Tsirkin
2014-06-02 21:58 ` Eric Dumazet
2014-06-03 12:48 ` Paolo Bonzini
2014-06-03 13:35 ` Vlad Yasevich [this message]
2014-06-03 13:55 ` Paolo Bonzini
2014-06-03 13:57 ` Eric Dumazet
2014-06-03 14:20 ` Paolo Bonzini
2014-06-04 19:51 ` Michael S. Tsirkin
2014-06-05 10:45 ` Michael S. Tsirkin
2014-06-04 18:12 ` Michael S. Tsirkin
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