From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [PATCH net 9/9] virtio-net: XDP support for small buffers Date: Tue, 3 Jan 2017 08:40:40 -0800 Message-ID: <586BD408.9030009@gmail.com> References: <1482503852-12438-1-git-send-email-jasowang@redhat.com> <1482503852-12438-10-git-send-email-jasowang@redhat.com> <586AD79B.2070203@gmail.com> <8c896c40-fd25-4b92-fe80-5be18c13dd48@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <8c896c40-fd25-4b92-fe80-5be18c13dd48@redhat.com> 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: Jason Wang , mst@redhat.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: john.r.fastabend@intel.com List-Id: virtualization@lists.linuxfoundation.org T24gMTctMDEtMDIgMTA6MTYgUE0sIEphc29uIFdhbmcgd3JvdGU6Cj4gCj4gCj4gT24gMjAxN+W5 tDAx5pyIMDPml6UgMDY6NDMsIEpvaG4gRmFzdGFiZW5kIHdyb3RlOgo+PiBPbiAxNi0xMi0yMyAw NjozNyBBTSwgSmFzb24gV2FuZyB3cm90ZToKPj4+IENvbW1pdCBmNjAwYjY5MDUwMTUgKCJ2aXJ0 aW9fbmV0OiBBZGQgWERQIHN1cHBvcnQiKSBsZWF2ZXMgdGhlIGNhc2Ugb2YKPj4+IHNtYWxsIHJl Y2VpdmUgYnVmZmVyIHVudG91Y2hlZC4gVGhpcyB3aWxsIGNvbmZ1c2UgdGhlIHVzZXIgd2hvIHdh bnQgdG8KPj4+IHNldCBYRFAgYnV0IHVzZSBzbWFsbCBidWZmZXJzLiBPdGhlciB0aGFuIGZvcmJp ZCBYRFAgaW4gc21hbGwgYnVmZmVyCj4+PiBtb2RlLCBsZXQncyBtYWtlIGl0IHdvcmsuIFhEUCB0 aGVuIGNhbiBvbmx5IHdvcmsgYXQgc2tiLT5kYXRhIHNpbmNlCj4+PiB2aXJ0aW8tbmV0IGNyZWF0 ZSBza2JzIGR1cmluZyByZWZpbGwsIHRoaXMgaXMgc3ViIG9wdGltYWwgd2hpY2ggY291bGQKPj4+ IGJlIG9wdGltaXplZCBpbiB0aGUgZnV0dXJlLgo+Pj4KPj4+IENjOiBKb2huIEZhc3RhYmVuZCA8 am9obi5yLmZhc3RhYmVuZEBpbnRlbC5jb20+Cj4+PiBTaWduZWQtb2ZmLWJ5OiBKYXNvbiBXYW5n IDxqYXNvd2FuZ0ByZWRoYXQuY29tPgo+Pj4gLS0tCj4+PiAgIGRyaXZlcnMvbmV0L3ZpcnRpb19u ZXQuYyB8IDExMiArKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKystLS0tLS0tLS0t LQo+Pj4gICAxIGZpbGUgY2hhbmdlZCwgODcgaW5zZXJ0aW9ucygrKSwgMjUgZGVsZXRpb25zKC0p Cj4+Pgo+PiBIaSBKYXNvbiwKPj4KPj4gSSB3YXMgZG9pbmcgc29tZSBtb3JlIHRlc3Rpbmcgb24g dGhpcyB3aGF0IGRvIHlvdSB0aGluayBhYm91dCBkb2luZyB0aGlzCj4+IHNvIHRoYXQgZnJlZV91 bnVzZWRfYnVmcygpIGhhbmRsZXMgdGhlIGJ1ZmZlciBmcmVlIHdpdGggZGV2X2tmcmVlX3NrYigp Cj4+IGluc3RlYWQgb2YgcHV0X3BhZ2UgaW4gc21hbGwgcmVjZWl2ZSBtb2RlLiBTZWVtcyBtb3Jl IGNvcnJlY3QgdG8gbWUuCj4+Cj4+Cj4+IGRpZmYgLS1naXQgYS9kcml2ZXJzL25ldC92aXJ0aW9f bmV0LmMgYi9kcml2ZXJzL25ldC92aXJ0aW9fbmV0LmMKPj4gaW5kZXggNzgzZTg0Mi4uMjdmZjc2 YyAxMDA2NDQKPj4gLS0tIGEvZHJpdmVycy9uZXQvdmlydGlvX25ldC5jCj4+ICsrKyBiL2RyaXZl cnMvbmV0L3ZpcnRpb19uZXQuYwo+PiBAQCAtMTg5OCw2ICsxODk4LDEwIEBAIHN0YXRpYyB2b2lk IGZyZWVfcmVjZWl2ZV9wYWdlX2ZyYWdzKHN0cnVjdCB2aXJ0bmV0X2luZm8KPj4gKnZpKQo+Pgo+ PiAgIHN0YXRpYyBib29sIGlzX3hkcF9xdWV1ZShzdHJ1Y3QgdmlydG5ldF9pbmZvICp2aSwgaW50 IHEpCj4+ICAgewo+PiArICAgICAgIC8qIEZvciBzbWFsbCByZWNlaXZlIG1vZGUgYWx3YXlzIHVz ZSBrZnJlZV9za2IgdmFyaWFudHMgKi8KPj4gKyAgICAgICBpZiAoIXZpLT5tZXJnZWFibGVfcnhf YnVmcykKPj4gKyAgICAgICAgICAgICAgIHJldHVybiBmYWxzZTsKPj4gKwo+PiAgICAgICAgICBp ZiAocSA8ICh2aS0+Y3Vycl9xdWV1ZV9wYWlycyAtIHZpLT54ZHBfcXVldWVfcGFpcnMpKQo+PiAg ICAgICAgICAgICAgICAgIHJldHVybiBmYWxzZTsKPj4gICAgICAgICAgZWxzZSBpZiAocSA8IHZp LT5jdXJyX3F1ZXVlX3BhaXJzKQo+Pgo+Pgo+PiBwYXRjaCBpcyB1bnRlc3RlZCBqdXN0IHNwb3R0 ZWQgZG9pbmcgY29kZSByZXZpZXcuCj4+Cj4+IFRoYW5rcywKPj4gSm9obgo+IAo+IFdlIHByb2Jh Ymx5IG5lZWQgYSBiZXR0ZXIgbmFtZSBmb3IgdGhpcyBmdW5jdGlvbi4KPiAKPiBBY2tlZC1ieTog SmFzb24gV2FuZyA8amFzb3dhbmdAcmVkaGF0LmNvbT4KPiAKCkhvdyBhYm91dCBpc194ZHBfcmF3 X2J1ZmZlcl9xdWV1ZSgpPwoKSSdsbCBzdWJtaXQgYSBwcm9wZXIgcGF0Y2ggdG9kYXkuCl9fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClZpcnR1YWxpemF0aW9u IG1haWxpbmcgbGlzdApWaXJ0dWFsaXphdGlvbkBsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9yZwpo dHRwczovL2xpc3RzLmxpbnV4Zm91bmRhdGlvbi5vcmcvbWFpbG1hbi9saXN0aW5mby92aXJ0dWFs aXphdGlvbg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759668AbdACQlA (ORCPT ); Tue, 3 Jan 2017 11:41:00 -0500 Received: from mail-pf0-f194.google.com ([209.85.192.194]:35495 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752930AbdACQk5 (ORCPT ); Tue, 3 Jan 2017 11:40:57 -0500 Subject: Re: [PATCH net 9/9] virtio-net: XDP support for small buffers To: Jason Wang , mst@redhat.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <1482503852-12438-1-git-send-email-jasowang@redhat.com> <1482503852-12438-10-git-send-email-jasowang@redhat.com> <586AD79B.2070203@gmail.com> <8c896c40-fd25-4b92-fe80-5be18c13dd48@redhat.com> Cc: john.r.fastabend@intel.com From: John Fastabend Message-ID: <586BD408.9030009@gmail.com> Date: Tue, 3 Jan 2017 08:40:40 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <8c896c40-fd25-4b92-fe80-5be18c13dd48@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17-01-02 10:16 PM, Jason Wang wrote: > > > On 2017年01月03日 06:43, John Fastabend wrote: >> On 16-12-23 06:37 AM, Jason Wang wrote: >>> Commit f600b6905015 ("virtio_net: Add XDP support") leaves the case of >>> small receive buffer untouched. This will confuse the user who want to >>> set XDP but use small buffers. Other than forbid XDP in small buffer >>> mode, let's make it work. XDP then can only work at skb->data since >>> virtio-net create skbs during refill, this is sub optimal which could >>> be optimized in the future. >>> >>> Cc: John Fastabend >>> Signed-off-by: Jason Wang >>> --- >>> drivers/net/virtio_net.c | 112 ++++++++++++++++++++++++++++++++++++----------- >>> 1 file changed, 87 insertions(+), 25 deletions(-) >>> >> Hi Jason, >> >> I was doing some more testing on this what do you think about doing this >> so that free_unused_bufs() handles the buffer free with dev_kfree_skb() >> instead of put_page in small receive mode. Seems more correct to me. >> >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index 783e842..27ff76c 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c >> @@ -1898,6 +1898,10 @@ static void free_receive_page_frags(struct virtnet_info >> *vi) >> >> static bool is_xdp_queue(struct virtnet_info *vi, int q) >> { >> + /* For small receive mode always use kfree_skb variants */ >> + if (!vi->mergeable_rx_bufs) >> + return false; >> + >> if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs)) >> return false; >> else if (q < vi->curr_queue_pairs) >> >> >> patch is untested just spotted doing code review. >> >> Thanks, >> John > > We probably need a better name for this function. > > Acked-by: Jason Wang > How about is_xdp_raw_buffer_queue()? I'll submit a proper patch today.