From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: Re: [PATCH v2 net-next 4/4] vhost_net: Avoid rx vring kicks during busyloop Date: Tue, 3 Jul 2018 17:05:22 +0800 Message-ID: References: <1530603094-2476-1-git-send-email-makita.toshiaki@lab.ntt.co.jp> <1530603094-2476-5-git-send-email-makita.toshiaki@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; Format="flowed" Content-Transfer-Encoding: base64 Cc: netdev@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org To: Toshiaki Makita , "David S. Miller" , "Michael S. Tsirkin" Return-path: In-Reply-To: <1530603094-2476-5-git-send-email-makita.toshiaki@lab.ntt.co.jp> Content-Language: en-US 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 List-Id: netdev.vger.kernel.org CgpPbiAyMDE45bm0MDfmnIgwM+aXpSAxNTozMSwgVG9zaGlha2kgTWFraXRhIHdyb3RlOgo+IFdl IG1heSBydW4gb3V0IG9mIGF2YWlsIHJ4IHJpbmcgZGVzY3JpcHRvciB1bmRlciBoZWF2eSBsb2Fk IGJ1dCBidXN5cG9sbAo+IGRpZCBub3QgZGV0ZWN0IGl0IHNvIGJ1c3lwb2xsIG1heSBoYXZlIGV4 aXRlZCBwcmVtYXR1cmVseS4gQXZvaWQgdGhpcyBieQo+IGNoZWNraW5nIHJ4IHJpbmcgZnVsbCBk dXJpbmcgYnVzeXBvbGwuCgpBY3R1YWxseSwgd2UncmUgY2hlY2tpbmcgd2hldGhlciBpdCB3YXMg ZW1wdHkgaW4gZmFjdD8KCj4KPiBTaWduZWQtb2ZmLWJ5OiBUb3NoaWFraSBNYWtpdGEgPG1ha2l0 YS50b3NoaWFraUBsYWIubnR0LmNvLmpwPgo+IC0tLQo+ICAgZHJpdmVycy92aG9zdC9uZXQuYyB8 IDEwICsrKysrKystLS0KPiAgIDEgZmlsZSBjaGFuZ2VkLCA3IGluc2VydGlvbnMoKyksIDMgZGVs ZXRpb25zKC0pCj4KPiBkaWZmIC0tZ2l0IGEvZHJpdmVycy92aG9zdC9uZXQuYyBiL2RyaXZlcnMv dmhvc3QvbmV0LmMKPiBpbmRleCA3OTFiYzhiLi5iMjI0MDM2IDEwMDY0NAo+IC0tLSBhL2RyaXZl cnMvdmhvc3QvbmV0LmMKPiArKysgYi9kcml2ZXJzL3Zob3N0L25ldC5jCj4gQEAgLTY1OCw2ICs2 NTgsNyBAQCBzdGF0aWMgaW50IHZob3N0X25ldF9yeF9wZWVrX2hlYWRfbGVuKHN0cnVjdCB2aG9z dF9uZXQgKm5ldCwgc3RydWN0IHNvY2sgKnNrLAo+ICAgewo+ICAgCXN0cnVjdCB2aG9zdF9uZXRf dmlydHF1ZXVlICpybnZxID0gJm5ldC0+dnFzW1ZIT1NUX05FVF9WUV9SWF07Cj4gICAJc3RydWN0 IHZob3N0X25ldF92aXJ0cXVldWUgKnRudnEgPSAmbmV0LT52cXNbVkhPU1RfTkVUX1ZRX1RYXTsK PiArCXN0cnVjdCB2aG9zdF92aXJ0cXVldWUgKnJ2cSA9ICZybnZxLT52cTsKPiAgIAlzdHJ1Y3Qg dmhvc3RfdmlydHF1ZXVlICp0dnEgPSAmdG52cS0+dnE7Cj4gICAJdW5zaWduZWQgbG9uZyB1bmlu aXRpYWxpemVkX3ZhcihlbmR0aW1lKTsKPiAgIAlpbnQgbGVuID0gcGVla19oZWFkX2xlbihybnZx LCBzayk7Cj4gQEAgLTY3Nyw3ICs2NzgsOCBAQCBzdGF0aWMgaW50IHZob3N0X25ldF9yeF9wZWVr X2hlYWRfbGVuKHN0cnVjdCB2aG9zdF9uZXQgKm5ldCwgc3RydWN0IHNvY2sgKnNrLAo+ICAgCQkJ CSpidXN5bG9vcF9pbnRyID0gdHJ1ZTsKPiAgIAkJCQlicmVhazsKPiAgIAkJCX0KPiAtCQkJaWYg KHNrX2hhc19yeF9kYXRhKHNrKSB8fAo+ICsJCQlpZiAoKHNrX2hhc19yeF9kYXRhKHNrKSAmJgo+ ICsJCQkgICAgICF2aG9zdF92cV9hdmFpbF9lbXB0eSgmbmV0LT5kZXYsIHJ2cSkpIHx8Cj4gICAJ CQkgICAgIXZob3N0X3ZxX2F2YWlsX2VtcHR5KCZuZXQtPmRldiwgdHZxKSkKPiAgIAkJCQlicmVh azsKPiAgIAkJCWNwdV9yZWxheCgpOwo+IEBAIC04MjcsNyArODI5LDYgQEAgc3RhdGljIHZvaWQg aGFuZGxlX3J4KHN0cnVjdCB2aG9zdF9uZXQgKm5ldCkKPiAgIAoKSSB0aG91Z2h0IGJlbG93IGNv ZGVzIHNob3VsZCBiZWxvbmcgdG8gcGF0Y2ggMy4gT3IgSSBtYXkgbWlzcyBzb21ldGhpbmcuCgpU aGFua3MKCj4gICAJd2hpbGUgKChzb2NrX2xlbiA9IHZob3N0X25ldF9yeF9wZWVrX2hlYWRfbGVu KG5ldCwgc29jay0+c2ssCj4gICAJCQkJCQkgICAgICAmYnVzeWxvb3BfaW50cikpKSB7Cj4gLQkJ YnVzeWxvb3BfaW50ciA9IGZhbHNlOwo+ICAgCQlzb2NrX2xlbiArPSBzb2NrX2hsZW47Cj4gICAJ CXZob3N0X2xlbiA9IHNvY2tfbGVuICsgdmhvc3RfaGxlbjsKPiAgIAkJaGVhZGNvdW50ID0gZ2V0 X3J4X2J1ZnModnEsIHZxLT5oZWFkcyArIG52cS0+ZG9uZV9pZHgsCj4gQEAgLTgzOCw3ICs4Mzks OSBAQCBzdGF0aWMgdm9pZCBoYW5kbGVfcngoc3RydWN0IHZob3N0X25ldCAqbmV0KQo+ICAgCQkJ Z290byBvdXQ7Cj4gICAJCS8qIE9LLCBub3cgd2UgbmVlZCB0byBrbm93IGFib3V0IGFkZGVkIGRl c2NyaXB0b3JzLiAqLwo+ICAgCQlpZiAoIWhlYWRjb3VudCkgewo+IC0JCQlpZiAodW5saWtlbHko dmhvc3RfZW5hYmxlX25vdGlmeSgmbmV0LT5kZXYsIHZxKSkpIHsKPiArCQkJaWYgKHVubGlrZWx5 KGJ1c3lsb29wX2ludHIpKSB7Cj4gKwkJCQl2aG9zdF9wb2xsX3F1ZXVlKCZ2cS0+cG9sbCk7Cj4g KwkJCX0gZWxzZSBpZiAodW5saWtlbHkodmhvc3RfZW5hYmxlX25vdGlmeSgmbmV0LT5kZXYsIHZx KSkpIHsKPiAgIAkJCQkvKiBUaGV5IGhhdmUgc2xpcHBlZCBvbmUgaW4gYXMgd2Ugd2VyZQo+ICAg CQkJCSAqIGRvaW5nIHRoYXQ6IGNoZWNrIGFnYWluLiAqLwo+ICAgCQkJCXZob3N0X2Rpc2FibGVf bm90aWZ5KCZuZXQtPmRldiwgdnEpOwo+IEBAIC04NDgsNiArODUxLDcgQEAgc3RhdGljIHZvaWQg aGFuZGxlX3J4KHN0cnVjdCB2aG9zdF9uZXQgKm5ldCkKPiAgIAkJCSAqIHRoZXkgcmVmaWxsZWQu ICovCj4gICAJCQlnb3RvIG91dDsKPiAgIAkJfQo+ICsJCWJ1c3lsb29wX2ludHIgPSBmYWxzZTsK PiAgIAkJaWYgKG52cS0+cnhfcmluZykKPiAgIAkJCW1zZy5tc2dfY29udHJvbCA9IHZob3N0X25l dF9idWZfY29uc3VtZSgmbnZxLT5yeHEpOwo+ICAgCQkvKiBPbiBvdmVycnVuLCB0cnVuY2F0ZSBh bmQgZGlzY2FyZCAqLwoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX18KVmlydHVhbGl6YXRpb24gbWFpbGluZyBsaXN0ClZpcnR1YWxpemF0aW9uQGxpc3RzLmxp bnV4LWZvdW5kYXRpb24ub3JnCmh0dHBzOi8vbGlzdHMubGludXhmb3VuZGF0aW9uLm9yZy9tYWls bWFuL2xpc3RpbmZvL3ZpcnR1YWxpemF0aW9u