From: Peter Zijlstra Subject: Re: nfs client lockdep warning Date: Fri, 09 Jan 2009 07:51:08 +0100 Message-ID: <1231483868.11687.523.camel@twins> References: <20090108203658.GE19312@fieldses.org> <1231447707.7179.10.camel@heimdal.trondhjem.org> <20090108212056.GF19312@fieldses.org> <20090109043315.GA12139@gondor.apana.org.au> <1231480697.11687.522.camel@twins> <20090109062333.GB13304@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain Cc: "J. Bruce Fields" , netdev@vger.kernel.org, linux-nfs@vger.kernel.org, Trond Myklebust , Ingo Molnar , Nick Piggin To: Herbert Xu Return-path: In-Reply-To: <20090109062333.GB13304@gondor.apana.org.au> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 2009-01-09 at 17:23 +1100, Herbert Xu wrote: > On Fri, Jan 09, 2009 at 06:58:17AM +0100, Peter Zijlstra wrote: > > > > > > > > Jan 8 15:29:17 ying3 kernel: [] copy_from_user+0x36/0x90 > > > > > > Jan 8 15:29:17 ying3 kernel: [] memcpy_fromiovecend+0x60/0x90 > > > > > > Jan 8 15:29:17 ying3 kernel: [] ip_generic_getfrag+0x9f/0xb0 > > > > > > Jan 8 15:29:17 ying3 kernel: [] ip_append_data+0x6bb/0x950 > > > > > > Jan 8 15:29:17 ying3 kernel: [] udp_sendmsg+0x2bd/0x680 > > > > > > Jan 8 15:29:17 ying3 kernel: [] inet_sendmsg+0x39/0x70 > > > > > > Jan 8 15:29:17 ying3 kernel: [] sock_sendmsg+0xd6/0x100 > > > > > > Jan 8 15:29:17 ying3 kernel: [] kernel_sendmsg+0x35/0x50 > > > > > > Jan 8 15:29:17 ying3 kernel: [] xs_send_kvec+0xa8/0xb0 > > > > > > Jan 8 15:29:17 ying3 kernel: [] xs_sendpages+0x71/0x210 > > > > > > Jan 8 15:29:17 ying3 kernel: [] xs_udp_send_request+0x40/0x120 > > > > > > Jan 8 15:29:17 ying3 kernel: [] xprt_transmit+0x6f/0x280 > > > > > > Jan 8 15:29:17 ying3 kernel: [] call_transmit+0x17f/0x250 > > > > > > Jan 8 15:29:17 ying3 kernel: [] __rpc_execute+0x73/0x250 > > > > Is there anything pinning that user-space page, if not its free to > > fault, which would mean its a real warning... > > It's kernel memory, not user memory. See xs_udp_send_request in > net/sunrpc. Ahh, so something like this ought to fix it I think... Signed-off-by: Peter Zijlstra --- diff --git a/mm/memory.c b/mm/memory.c index 7b9db65..a2ed52e 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3079,6 +3079,9 @@ void print_vma_addr(char *prefix, unsigned long ip) #ifdef CONFIG_PROVE_LOCKING void might_fault(void) { + if (get_fs() == KERNEL_DS) + return; + might_sleep(); /* * it would be nicer only to annotate paths which are not under