From: Patrick McHardy <kaber@trash.net>
To: David Miller <davem@davemloft.net>
Cc: tgraf@suug.ch, juliusv@google.com, netdev@vger.kernel.org,
vbusam@google.com
Subject: Re: Sending big Netlink messages to userspace
Date: Thu, 26 Jun 2008 02:41:20 +0200 [thread overview]
Message-ID: <4862E5B0.9080007@trash.net> (raw)
In-Reply-To: <20080625.155146.103043993.davem@davemloft.net>
David Miller wrote:
> From: Thomas Graf <tgraf@suug.ch>
> Date: Wed, 25 Jun 2008 12:44:01 +0200
>
>> libnl initializes the buffer size to the size of a page. The value
>> can be overwritten by calling nl_set_buffer_size(socket, rx, tx)
>
> And it doesn't need to be any larger than a page. Actually, the
> hard upper bound is 8K.
>
> The kernel will always chop the response up into chunks of that
> size or smaller when generating replies to userspace.
>
> Therefore userland need never have a buffer larger than 8K or
> sysconf(_SC_PAGESIZE), whichever is smaller.
For dumps the size is fine, for large unicast messages it
might need to be increased though (like nfnetlink_queue).
next prev parent reply other threads:[~2008-06-26 0:41 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-24 16:38 Sending big Netlink messages to userspace Julius Volz
2008-06-24 17:00 ` Patrick McHardy
2008-06-24 18:18 ` Julius Volz
2008-06-25 10:44 ` Thomas Graf
2008-06-25 18:56 ` Julius Volz
2008-06-26 10:01 ` Thomas Graf
2008-06-25 22:51 ` David Miller
2008-06-26 0:41 ` Patrick McHardy [this message]
2008-06-26 15:39 ` Julius Volz
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