From: Eric Dumazet <eric.dumazet@gmail.com>
To: Xin Long <lucien.xin@gmail.com>, Eric Dumazet <edumazet@google.com>
Cc: "David S . Miller" <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
syzbot <syzkaller@googlegroups.com>,
tipc-discussion@lists.sourceforge.net, jmaloy@redhat.com
Subject: Re: [PATCH net] tipc: block BH before using dst_cache
Date: Fri, 22 May 2020 08:52:36 -0700 [thread overview]
Message-ID: <806eda1a-de5a-22f3-b5bf-3189878b8b55@gmail.com> (raw)
In-Reply-To: <CADvbK_eJx=PyH8MDCWQJMRW-p+nv9QtuQGG2TtYX=9n9oY7rJg@mail.gmail.com>
On 5/21/20 11:18 PM, Xin Long wrote:
> On Fri, May 22, 2020 at 1:55 PM Eric Dumazet <edumazet@google.com> wrote:
>>
>> Resend to the list in non HTML form
>>
>>
>> On Thu, May 21, 2020 at 10:53 PM Eric Dumazet <edumazet@google.com> wrote:
>>>
>>>
>>>
>>> On Thu, May 21, 2020 at 10:50 PM Xin Long <lucien.xin@gmail.com> wrote:
>>>>
>>>> On Fri, May 22, 2020 at 2:30 AM Eric Dumazet <edumazet@google.com> wrote:
>>>>>
>>>>> dst_cache_get() documents it must be used with BH disabled.
>>>> Interesting, I thought under rcu_read_lock() is enough, which calls
>>>> preempt_disable().
>>>
>>>
>>> rcu_read_lock() does not disable BH, never.
>>>
>>> And rcu_read_lock() does not necessarily disable preemption.
> Then I need to think again if it's really worth using dst_cache here.
>
> Also add tipc-discussion and Jon to CC list.
>
> Thanks.
What improvements you got with your patch ?
Disabling BH a bit earlier wont make any difference.
next prev parent reply other threads:[~2020-05-22 15:52 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-21 18:29 [PATCH net] tipc: block BH before using dst_cache Eric Dumazet
2020-05-22 5:56 ` Xin Long
[not found] ` <CANn89i+x=xbXoKekC6bF_ZMBRMY_mkmuVbNSW3LcRncsiZGd_g@mail.gmail.com>
2020-05-22 5:55 ` Eric Dumazet
2020-05-22 6:18 ` Xin Long
2020-05-22 15:01 ` Jon Maloy
2020-05-22 15:57 ` Eric Dumazet
2020-05-22 19:47 ` Jon Maloy
2020-05-22 20:10 ` Eric Dumazet
2020-05-22 21:37 ` Jon Maloy
2020-05-22 21:44 ` Eric Dumazet
2020-05-23 0:28 ` Tetsuo Handa
2020-05-22 15:52 ` Eric Dumazet [this message]
2020-05-22 22:39 ` David Miller
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