From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH 20/20] iscsi: support for swapping over iSCSI. From: Peter Zijlstra In-Reply-To: <1158266150.30737.92.camel@taijtu> References: <20060912143049.278065000@chello.nl> <20060912144905.201160000@chello.nl> <45086F16.9030307@cs.wisc.edu> <1158214650.13665.27.camel@twins> <4509ABE5.2080904@cs.wisc.edu> <1158266150.30737.92.camel@taijtu> Content-Type: text/plain Date: Thu, 14 Sep 2006 22:46:56 +0200 Message-Id: <1158266816.30737.99.camel@taijtu> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Mike Christie Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Linus Torvalds , Andrew Morton , David Miller , Rik van Riel , Daniel Phillips List-ID: On Thu, 2006-09-14 at 22:35 +0200, Peter Zijlstra wrote: > On Thu, 2006-09-14 at 14:22 -0500, Mike Christie wrote: > > > I thought I found allocations in that path, lemme search... > > > found this: > > > > > > iscsi_tcp_data_recv() > > > iscsi_data_rescv() > > > iscsi_complete_pdu() > > > __iscsi_complete_pdu() > > > iscsi_recv_pdu() > > > alloc_skb( GFP_ATOMIC); > > > > > > > You are right that is for the netlink interface. Could we move the > > PF_MEMALLOC setting and clearing to iscsi_recv_pdu and and add it to > > iscsi_conn_error in scsi_transport_iscsi.c so that iscsi_iser and > > qla4xxx will have it set when they need it. I will send a patch for this > > along with a way to have the netlink sock vmio set for all iscsi drivers > > that need it. > > I already have such a patch, look at: > http://programming.kicks-ass.net/kernel-patches/vm_deadlock/current/iscsi_vmio.patch > > but what conditional do you want to use for PF_MEMALLOC, an > unconditional setting will be highly unpopular. > > Hmm, perhaps you could key it of sk_has_vmio(nls)... On second thought, not such a good idea, that will still be too course. You only want to force feed stuff originating from sk_has_vmio(iscsi_tcp_conn->sock->sk) connections, not all connectections as soon as there is a swapper in the system. In order to preserve that information you need extra state, abusing this process flags is as good as propagating __GFP_EMERGENCY down the call chain with extra gfp_t arguments, perhaps even better, since it will make sure we catch all allocations. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org