From: David Miller <davem@davemloft.net>
To: timo.teras@iki.fi
Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org
Subject: Re: [PATCH] ipv4: synchronize bind() with RTM_NEWADDR notifications
Date: Thu, 21 Oct 2010 04:03:19 -0700 (PDT) [thread overview]
Message-ID: <20101021.040319.191412436.davem@davemloft.net> (raw)
In-Reply-To: <4CC01CC0.7090101@iki.fi>
From: Timo Teräs <timo.teras@iki.fi>
Date: Thu, 21 Oct 2010 13:58:08 +0300
> On 10/21/2010 01:50 PM, David Miller wrote:
>> From: Timo Teräs <timo.teras@iki.fi>
>> Date: Thu, 21 Oct 2010 13:41:37 +0300
>>
>>> Is inet_bind() called from non-userland context? If yes, then this is a
>>> bad idea. Otherwise I don't think it's that hot path...
>>
>> It is.
>
> Yet, almost immediately after that there is lock_sock() which can also
> sleep. How does that work then?
RTNL interlocks globally with a heavy primitive, a mutex, lock_sock()
grabs a spinlcok which is local to the socket's context.
So if we have 100,000 sockets binding we'll suck with you're change
whereas the lock_sock() does not cause that problem.
Is this so difficult for you to comprehend?
next prev parent reply other threads:[~2010-10-21 11:02 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-21 10:12 [PATCH] ipv4: synchronize bind() with RTM_NEWADDR notifications Timo Teräs
2010-10-21 10:25 ` Eric Dumazet
2010-10-21 10:41 ` Timo Teräs
2010-10-21 10:50 ` David Miller
2010-10-21 10:58 ` Timo Teräs
2010-10-21 11:03 ` David Miller [this message]
2010-10-21 11:29 ` Timo Teräs
2010-10-21 11:34 ` David Miller
2010-10-21 11:57 ` Timo Teräs
2010-10-21 13:06 ` [PATCH v2] " Timo Teräs
2010-10-21 14:10 ` Eric Dumazet
2010-10-21 19:01 ` Timo Teräs
2010-10-21 11:12 ` [PATCH] " Eric Dumazet
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