From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [net-next PATCH V2] virtio-net: switch to use XPS to choose txq Date: Wed, 2 Oct 2013 09:15:45 +0300 Message-ID: <20131002061545.GA6880@redhat.com> References: <1380526637-35524-1-git-send-email-jasowang@redhat.com> <20130930.221040.543720988967287293.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <20130930.221040.543720988967287293.davem@davemloft.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: David Miller Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org T24gTW9uLCBTZXAgMzAsIDIwMTMgYXQgMTA6MTA6NDBQTSAtMDcwMCwgRGF2aWQgTWlsbGVyIHdy b3RlOgo+IEZyb206IEphc29uIFdhbmcgPGphc293YW5nQHJlZGhhdC5jb20+Cj4gRGF0ZTogTW9u LCAzMCBTZXAgMjAxMyAxNTozNzoxNyArMDgwMAo+IAo+ID4gV2UgdXNlZCB0byB1c2UgYSBwZXJj cHUgc3RydWN0dXJlIHZxX2luZGV4IHRvIHJlY29yZCB0aGUgY3B1IHRvIHF1ZXVlCj4gPiBtYXBw aW5nLCB0aGlzIGlzIHN1Ym9wdGltYWwgc2luY2UgaXQgZHVwbGljYXRlcyB0aGUgd29yayBvZiBY UFMgYW5kCj4gPiBsb3NlcyBhbGwgb3RoZXIgWFBTIGZ1bmN0aW9uYWxpdHkgc3VjaCBhcyBhbGxv d2luZyB1c2UgdG8gY29uZmlndXJlCj4gPiB0aGVpciBvd24gdHJhbnNtaXNzaW9uIHN0ZWVyaW5n IHN0cmF0ZWd5Lgo+ID4gCj4gPiBTbyB0aGlzIHBhdGNoIHN3aXRjaGVzIHRvIHVzZSBYUFMgYW5k IHN1Z2dlc3QgYSBkZWZhdWx0IG1hcHBpbmcgd2hlbgo+ID4gdGhlIG51bWJlciBvZiBjcHVzIGlz IGVxdWFsIHRvIHRoZSBudW1iZXIgb2YgcXVldWVzLiBXaXRoIFhQUyBzdXBwb3J0LAo+ID4gdGhl cmUncyBubyBuZWVkIGZvciBrZWVwaW5nIHBlci1jcHUgdnFfaW5kZXggYW5kIC5uZG9fc2VsZWN0 X3F1ZXVlKCksCj4gPiBzbyB0aGV5IHdlcmUgcmVtb3ZlZCBhbHNvLgo+ID4gCj4gPiBDYzogUnVz dHkgUnVzc2VsbCA8cnVzdHlAcnVzdGNvcnAuY29tLmF1Pgo+ID4gQ2M6IE1pY2hhZWwgUy4gVHNp cmtpbiA8bXN0QHJlZGhhdC5jb20+Cj4gPiBTaWduZWQtb2ZmLWJ5OiBKYXNvbiBXYW5nIDxqYXNv d2FuZ0ByZWRoYXQuY29tPgo+ID4gLS0tCj4gPiBDaGFuZ2VzIGZyb20gVjE6Cj4gPiAtIHVzZSBj cHVtYXNrX29mKCkgaW5zdGVhZCBvZiBhbGxvY2F0ZSBkeW5hbWljYWxseQo+IAo+IFRoaXMgZ2Vu ZXJhdGVzIGJ1aWxkIHdhcm5pbmdzOgo+IAo+IGRyaXZlcnMvbmV0L3ZpcnRpb19uZXQuYzogSW4g ZnVuY3Rpb24g4oCYdmlydG5ldF9zZXRfYWZmaW5pdHnigJk6Cj4gZHJpdmVycy9uZXQvdmlydGlv X25ldC5jOjEwOTM6Mzogd2FybmluZzogcGFzc2luZyBhcmd1bWVudCAyIG9mIOKAmG5ldGlmX3Nl dF94cHNfcXVldWXigJkgZGlzY2FyZHMg4oCYY29uc3TigJkgcXVhbGlmaWVyIGZyb20gcG9pbnRl ciB0YXJnZXQgdHlwZSBbZW5hYmxlZCBieSBkZWZhdWx0XQo+IEluIGZpbGUgaW5jbHVkZWQgZnJv bSBkcml2ZXJzL25ldC92aXJ0aW9fbmV0LmM6MjA6MDoKPiBpbmNsdWRlL2xpbnV4L25ldGRldmlj ZS5oOjIyNzU6NTogbm90ZTogZXhwZWN0ZWQg4oCYc3RydWN0IGNwdW1hc2sgKuKAmSBidXQgYXJn dW1lbnQgaXMgb2YgdHlwZSDigJhjb25zdCBzdHJ1Y3QgY3B1bWFzayAq4oCZCgpMb29rcyBsaWtl IHdlIGp1c3QgbmVlZCB0byB0d2VhayB0aGUgc2lnbmF0dXJlIHRoZXJlIHRvIGNvbnN0IHN0cnVj dApjcHVtYXNrICo6IGl0J3MgbmV2ZXIgY2hhbmdlZC4KCkkganVzdCBzZW50IGEgcGF0Y2gKCVtQ QVRDSF0gbmV0aWZfc2V0X3hwc19xdWV1ZTogbWFrZSBjcHUgbWFzayBjb25zdAp0aGF0IGRvZXMg ZXhhY3RseSB0aGF0LgoKLS0gCk1TVApfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fXwpWaXJ0dWFsaXphdGlvbiBtYWlsaW5nIGxpc3QKVmlydHVhbGl6YXRpb25A bGlzdHMubGludXgtZm91bmRhdGlvbi5vcmcKaHR0cHM6Ly9saXN0cy5saW51eGZvdW5kYXRpb24u b3JnL21haWxtYW4vbGlzdGluZm8vdmlydHVhbGl6YXRpb24= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753279Ab3JBGNa (ORCPT ); Wed, 2 Oct 2013 02:13:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62465 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753069Ab3JBGN2 (ORCPT ); Wed, 2 Oct 2013 02:13:28 -0400 Date: Wed, 2 Oct 2013 09:15:45 +0300 From: "Michael S. Tsirkin" To: David Miller Cc: jasowang@redhat.com, rusty@rustcorp.com.au, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [net-next PATCH V2] virtio-net: switch to use XPS to choose txq Message-ID: <20131002061545.GA6880@redhat.com> References: <1380526637-35524-1-git-send-email-jasowang@redhat.com> <20130930.221040.543720988967287293.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20130930.221040.543720988967287293.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 30, 2013 at 10:10:40PM -0700, David Miller wrote: > From: Jason Wang > Date: Mon, 30 Sep 2013 15:37:17 +0800 > > > We used to use a percpu structure vq_index to record the cpu to queue > > mapping, this is suboptimal since it duplicates the work of XPS and > > loses all other XPS functionality such as allowing use to configure > > their own transmission steering strategy. > > > > So this patch switches to use XPS and suggest a default mapping when > > the number of cpus is equal to the number of queues. With XPS support, > > there's no need for keeping per-cpu vq_index and .ndo_select_queue(), > > so they were removed also. > > > > Cc: Rusty Russell > > Cc: Michael S. Tsirkin > > Signed-off-by: Jason Wang > > --- > > Changes from V1: > > - use cpumask_of() instead of allocate dynamically > > This generates build warnings: > > drivers/net/virtio_net.c: In function ‘virtnet_set_affinity’: > drivers/net/virtio_net.c:1093:3: warning: passing argument 2 of ‘netif_set_xps_queue’ discards ‘const’ qualifier from pointer target type [enabled by default] > In file included from drivers/net/virtio_net.c:20:0: > include/linux/netdevice.h:2275:5: note: expected ‘struct cpumask *’ but argument is of type ‘const struct cpumask *’ Looks like we just need to tweak the signature there to const struct cpumask *: it's never changed. I just sent a patch [PATCH] netif_set_xps_queue: make cpu mask const that does exactly that. -- MST