From: Marc Aurele La France <tsi@ualberta.ca>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>,
Stephen Hemminger <shemminger@vyatta.com>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
"Pekka Savola (ipv6)" <pekkas@netcore.fi>,
James Morris <jmorris@namei.org>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Patrick McHardy <kaber@trash.net>
Subject: Re: RFC: MTU for serving NFS on Infiniband
Date: Tue, 24 Aug 2010 14:33:02 -0600 (Mountain Daylight Time) [thread overview]
Message-ID: <alpine.WNT.2.00.1008241422540.312@cluij.ucs.ualberta.ca> (raw)
In-Reply-To: <1282680572.2467.78.camel@edumazet-laptop>
[-- Attachment #1: Type: TEXT/PLAIN, Size: 3433 bytes --]
On Tue, 24 Aug 2010, Eric Dumazet wrote:
> Le mardi 24 août 2010 à 13:49 -0600, Marc Aurele La France a écrit :
>> Any payload has to either fit in the MTU, or has to be broken up into
>> MTU-sized (or less) fragments, come hell or high water. That this is done
>> centrally is a good thing. It is the "(or less)" part that I am working
>> towards here.
> Could you post a full stack trace, to help me understand the path from
> NFS to ip_append_data ?
[<ffffffff810a5abe>] __alloc_pages_nodemask+0x617/0x692
[<ffffffff81061688>] ? mark_held_locks+0x49/0x64
[<ffffffff810d018b>] kmalloc_large_node+0x61/0x9e
[<ffffffff810d3050>] __kmalloc_node_track_caller+0x32/0x159
[<ffffffff812612da>] ? sock_alloc_send_pskb+0xc9/0x2ea
[<ffffffff81265cc6>] __alloc_skb+0x74/0x163
[<ffffffff812612da>] sock_alloc_send_pskb+0xc9/0x2ea
[<ffffffff81061688>] ? mark_held_locks+0x49/0x64
[<ffffffff81261510>] sock_alloc_send_skb+0x15/0x17
[<ffffffff81299317>] ip_append_data+0x500/0x9d0
[<ffffffff8103feae>] ? local_bh_enable+0xb7/0xbd
[<ffffffff8129a804>] ? ip_generic_getfrag+0x0/0x92
[<ffffffff81292bcd>] ? ip_route_output_flow+0x82/0x1f9
[<ffffffff812b8990>] udp_sendmsg+0x4ec/0x60c
[<ffffffff812bf2ac>] inet_sendmsg+0x4b/0x58
[<ffffffff8125dd89>] sock_sendmsg+0xd9/0xfa
[<ffffffff81063fb0>] ? __lock_acquire+0x787/0x7f5
[<ffffffff81063fb0>] ? __lock_acquire+0x787/0x7f5
[<ffffffff8125fcf5>] kernel_sendmsg+0x37/0x43
[<ffffffffa0267cd2>] xs_send_kvec+0x88/0x93 [sunrpc]
[<ffffffff812f08dc>] ? _raw_spin_unlock_irqrestore+0x44/0x4c
[<ffffffffa0267d5c>] xs_sendpages+0x7f/0x1be [sunrpc]
[<ffffffffa026952f>] xs_udp_send_request+0x5b/0x103 [sunrpc]
[<ffffffffa0266c0a>] xprt_transmit+0x11f/0x1f5 [sunrpc]
[<ffffffffa02ea140>] ? nfs3_xdr_writeargs+0x0/0x82 [nfs]
[<ffffffffa02648b9>] call_transmit+0x218/0x25e [sunrpc]
[<ffffffffa026aced>] __rpc_execute+0x9b/0x288 [sunrpc]
[<ffffffffa026aeef>] rpc_async_schedule+0x15/0x17 [sunrpc]
[<ffffffff81051137>] worker_thread+0x1ed/0x2e6
[<ffffffff810510e1>] ? worker_thread+0x197/0x2e6
[<ffffffffa026aeda>] ? rpc_async_schedule+0x0/0x17 [sunrpc]
[<ffffffff8105450f>] ? autoremove_wake_function+0x0/0x3d
[<ffffffff81050f4a>] ? worker_thread+0x0/0x2e6
[<ffffffff810541b2>] kthread+0x82/0x8a
[<ffffffff81002f14>] kernel_thread_helper+0x4/0x10
[<ffffffff81030d20>] ? finish_task_switch+0x0/0xd6
[<ffffffff81002f10>] ? kernel_thread_helper+0x0/0x10
There are many other variations as well.
> I suspect this is UDP transport ?
Yes.
> This reminds me a patch I wrote for IPV6 : We were allocating a huge
> (MTU sized) buffer, just to fill few bytes in it...
Humm. Interesting. Thanks for the pointer.
Marc.
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next prev parent reply other threads:[~2010-08-24 20:33 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-23 14:44 RFC: MTU for serving NFS on Infiniband Marc Aurele La France
2010-08-23 15:05 ` Stephen Hemminger
2010-08-24 15:14 ` Marc Aurele La France
2010-08-24 17:57 ` Ben Hutchings
2010-08-24 19:49 ` Marc Aurele La France
2010-08-24 20:09 ` Eric Dumazet
2010-08-24 20:33 ` Marc Aurele La France [this message]
2010-08-24 22:20 ` Ben Hutchings
2010-08-24 22:39 ` Stephen Hemminger
2010-08-25 5:54 ` Eric Dumazet
2010-08-25 12:10 ` Alexey Kuznetsov
2010-08-25 12:17 ` Eric Dumazet
2010-08-26 11:40 ` Marc Aurele La France
2010-08-26 11:57 ` Eric Dumazet
2010-08-26 14:43 ` Marc Aurele La France
2010-08-26 23:53 ` Stephen Hemminger
2010-08-27 0:06 ` David Miller
2010-08-27 16:20 ` Roland Dreier
2010-08-27 17:16 ` Roland Dreier
2010-08-27 17:53 ` Marc Aurele La France
2010-08-26 14:58 ` Chuck Lever
2010-09-30 18:50 ` Marc Aurele La France
2010-08-23 15:12 ` Ben Hutchings
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