Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752245Ab0FWJxG (ORCPT ); Wed, 23 Jun 2010 05:53:06 -0400 Received: from helcar.apana.org.au ([209.40.204.226]:59936 "EHLO fornost.hengli.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751056Ab0FWJxE (ORCPT ); Wed, 23 Jun 2010 05:53:04 -0400 Date: Wed, 23 Jun 2010 19:52:54 +1000 From: Herbert Xu To: "Dong, Eddie" Cc: "Xin, Xiaohui" , Stephen Hemminger , "netdev@vger.kernel.org" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "mst@redhat.com" , "mingo@elte.hu" , "davem@davemloft.net" , "jdike@linux.intel.com" Subject: Re: [RFC PATCH v7 01/19] Add a new structure for skb buffer from external. Message-ID: <20100623095254.GA32491@gondor.apana.org.au> References: <1275732899-5423-1-git-send-email-xiaohui.xin@intel.com> <20100606161348.427822fb@nehalam> <20100608052744.GA21547@gondor.apana.org.au> <20100611052112.GA25649@gondor.apana.org.au> <20100617112119.GB1515@gondor.apana.org.au> <1A42CE6F5F474C41B63392A5F80372B21F58CD9A@shsmsx501.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1A42CE6F5F474C41B63392A5F80372B21F58CD9A@shsmsx501.ccr.corp.intel.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1121 Lines: 22 On Wed, Jun 23, 2010 at 04:09:40PM +0800, Dong, Eddie wrote: > > Xiaohui & Herbert: > Mixing copy of head & 0-copy of bulk data imposes additional challange to find the guest buffer. The backend driver may be unable to find a spare guest buffer from virtqueue at that time which may block the receiving process then. > Can't we completely eliminate netdev_alloc_skb here? Assigning guest buffer at this time makes life much easier. I'm not sure I understand you concern. If you mean that when the guest doesn't give enough pages to the host and the host can't receive on behalf of the guest then isn't that already the case with the original patch-set? Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/