From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jon Rosen (jrosen)" Subject: RE: [PATCH v2] packet: track ring entry use using a shadow ring to prevent RX ring overrun Date: Tue, 22 May 2018 14:12:13 +0000 Message-ID: <00de829386b04823bb58a555fb620317@XCH-RTP-016.cisco.com> References: <1526731655-10087-1-git-send-email-jrosen@cisco.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Cc: "David S. Miller" , Willem de Bruijn , Eric Dumazet , Kees Cook , David Windsor , "Rosen, Rami" , "Reshetova, Elena" , "Mike Maloney" , Benjamin Poirier , "Thomas Gleixner" , Greg Kroah-Hartman , "open list:NETWORKING [GENERAL]" , open list To: Willem de Bruijn Return-path: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org T24gTW9uZGF5LCBNYXkgMjEsIDIwMTggMjoxNyBQTSwgSm9uIFJvc2VuIChqcm9zZW4pIDxqcm9z ZW5AY2lzY28uY29tPiB3cm90ZToNCj4gT24gTW9uZGF5LCBNYXkgMjEsIDIwMTggMTowNyBQTSwg V2lsbGVtIGRlIEJydWlqbg0KPiA8d2lsbGVtZGVicnVpam4ua2VybmVsQGdtYWlsLmNvbT4gd3Jv dGU6DQo+PiBPbiBNb24sIE1heSAyMSwgMjAxOCBhdCA4OjU3IEFNLCBKb24gUm9zZW4gKGpyb3Nl bikgPGpyb3NlbkBjaXNjby5jb20+IHdyb3RlOg0KDQouLi5zbmlwLi4uDQoNCj4+DQo+PiBBIHNl dHNvY2tvcHQgZm9yIHVzZXJzcGFjZSB0byBzaWduYWwgYSBzdHJpY3RlciBpbnRlcnByZXRhdGlv biBvZg0KPj4gdHBfc3RhdHVzIHRvIGVsaWRlIHRoZSBzaGFkb3cgaGFjayBjb3VsZCB0aGVuIGJl IGNvbnNpZGVyZWQuDQo+PiBJdCdzIG5vdCBwcmV0dHkuIEVpdGhlciB3YXksIG5vIGZ1bGwgbmV3 IHZlcnNpb24gaXMgcmVxdWlyZWQuDQo+Pg0KPj4+IEFzIG11Y2ggYXMgSSB3b3VsZCBsaWtlIHRv IGZpbmQgYSBzb2x1dGlvbiB0aGF0IGRvZXNuJ3QgcmVxdWlyZQ0KPj4+IHRoZSBzcGluIGxvY2sg SSBoYXZlIHlldCB0byBkbyBzby4gTWF5YmUgdGhlIGFuc3dlciBpcyB0aGF0DQo+Pj4gZXhpc3Rp bmcgYXBwbGljYXRpb25zIHdpbGwgbmVlZCB0byBzdWZmZXIgdGhlIHBlcmZvcm1hbmNlIGltcGFj dA0KPj4+IGJ1dCBhIG5ldyB2ZXJzaW9uIG9yIG9wdGlvbiBmb3IgVFBBQ0tFVF9WMS9WMiBjb3Vs ZCBiZSBhZGRlZCB0bw0KPj4+IGluZGljYXRlIHN0cmljdCBhZGhlcmVuY2Ugb2YgdGhlIFRQX1NU QVRVU19VU0VSIGJpdCBhbmQgdGhlbiB0aGUNCj4+PiBvcmlnaW5hbCBkaWZmcyBjb3VsZCBiZSB1 c2VkLg0KDQpJdCBsb29rcyBsaWtlIGFkZGluZyBuZXcgc29ja2V0IG9wdGlvbnMgaXMgcHJldHR5 IHJhcmUgc28gSQ0Kd29uZGVyIGlmIGEgYmV0dGVyIG9wdGlvbiBtaWdodCBiZSB0byBkZWZpbmUg YSBuZXcgVFBfU1RBVFVTX1hYWA0KYml0IHdoaWNoIHdvdWxkIHNpZ25hbCBmcm9tIGEgdXNlcnNw YWNlIGFwcGxpY2F0aW9uIHRvIHRoZSBrZXJuZWwNCnRoYXQgaXQgc3RyaWN0bHkgaW50ZXJwcmV0 cyB0aGUgVFBfU1RBVFVTX1VTRVIgYml0IHRvIGRldGVybWluZQ0Kb3duZXJzaGlwLg0KDQpUb2Rh eXMgYXBwbGljYXRpb25zIHNldCB0cF9zdGF0dXMgPSBUUF9TVEFUVVNfS0VSTkVMKDApIGZvciB0 aGUNCmtlcm5lbCB0byBwaWNrIHVwIHRoZSBlbnRyeS4gIFdlIGNvdWxkIGRlZmluZSBhIG5ldyB2 YWx1ZSB0byBwYXNzDQpvd25lcnNoaXAgYXMgd2VsbCBhcyBvbmUgdG8gaW5kaWNhdGUgdG8gb3Ro ZXIga2VybmVsIHRocmVhZHMgdGhhdA0KYW4gZW50cnkgaXMgaW51c2U6DQoNCiAgICAgICAgI2Rl ZmluZSBUUF9TVEFUVVNfVVNFUl9UT19LRVJORUwgICAgICAgICgxIDw8IDgpDQogICAgICAgICNk ZWZpbmUgVFBfU1RBVFVTX0lOVVNFICAgICAgICAgICAgICAgICAoMSA8PCA5KQ0KDQpJZiB0aGUg a2VybmVsIHNlZXMgdHBfc3RhdHVzID09IFRQX1NUQVRVU19LRVJORUwgdGhlbiBpdCBzaG91bGQN CnVzZSB0aGUgc2hhZG93IG1ldGhvZCBmb3IgdGFja2luZyBvd25lcnNoaXAuIElmIGl0IHNlZXMg dHBfc3RhdHVzDQo9PSBUUF9TVEFUVVNfVVNFUl9UT19LRVJORUwgdGhlbiBpdCBjYW4gdXNlIHRo ZSBUUF9TVEFUVVNfSU5VU0UNCm1ldGhvZC4NCg0KPj4+DQo+Pj4gVGhlcmUgaXMgYW5vdGhlciBv cHRpb24gSSB3YXMgY29uc2lkZXJpbmcgYnV0IGhhdmUgeWV0IHRvIHRyeQ0KPj4+IHdoaWNoIHdv dWxkIGF2b2lkIG5lZWRpbmcgYSBzaGFkb3cgcmluZyBieSB1c2luZyBjb3VudGVyKHMpIHRvDQo+ Pj4gdHJhY2sgbWF4aW11bSBzZXF1ZW5jZSBudW1iZXIgcXVldWVkIHRvIHVzZXJzcGFjZSB2cy4g dGhlIG5leHQNCj4+PiBzZXF1ZW5jZSBudW1iZXIgdG8gYmUgYWxsb2NhdGVkIGluIHRoZSByaW5n LiAgSWYgdGhlIGRpZmZlcmVuY2UNCj4+PiBpcyBncmVhdGVyIHRoYW4gdGhlIHNpemUgb2YgdGhl IHJpbmcgdGhlbiB0aGUgcmluZyBjYW4gYmUNCj4+PiBjb25zaWRlcmVkIGZ1bGwgYW5kIHRoZSBh bGxvY2F0aW9uIHdvdWxkIGZhaWwuIE9mIGNvdXJzZSB0aGlzIG1heQ0KPj4+IGNyZWF0ZSBhbiBh ZGRpdGlvbmFsIGhvdHNwb3QgYmV0d2VlbiBjb3Jlcywgbm90IHN1cmUgaWYgdGhhdA0KPj4+IHdv dWxkIGJlIHNpZ25pZmljYW50IG9yIG5vdC4NCj4+DQo+PiBQbGVhc2UgZG8gaGF2ZSBhIGxvb2ss IGJ1dCBJIGRvbid0IHRoaW5rIHRoYXQgdGhpcyB3aWxsIHdvcmsgaW4gdGhpcw0KPj4gY2FzZSBp biBwcmFjdGljZS4gSXQgcmVxdWlyZXMgdHJhY2tpbmcgdGhlIHByb2R1Y2VyIHRhaWwuIFVwZGF0 aW5nDQo+PiB0aGUgc2xvd2VzdCB3cml0ZXIgcmVxdWlyZXMgcHJvYmluZyBlYWNoIHN1YnNlcXVl bnQgc2xvdCdzIHN0YXR1cw0KPj4gYnl0ZSB0byBmaW5kIHRoZSBuZXcgdGFpbCwgd2hpY2ggaXMg YSBsb3Qgb2YgKGJ5IHRoZW4gY29sZCkgY2FjaGVsaW5lDQo+PiByZWFkcy4NCj4NCj4gSSd2ZSB0 aG91Z2h0IGFib3V0IGl0IGEgbGl0dGxlIG1vcmUgYW5kIGFtIG5vdCBjb252aW5jZWQgaXQncw0K PiB3b3JrYWJsZSBidXQgSSdsbCBzcGVuZCBhIGxpdHRsZSBtb3JlIHRpbWUgb24gaXQgYmVmb3Jl IGdpdmluZw0KPiB1cC4NCg0KSSd2ZSBnaXZlbiB1cCBvbiB0aGlzIG1ldGhvZC4gIEp1c3QgZG9u J3Qgc2VlIGhvdyB0byBtYWtlIGl0IHdvcmsuDQoNCg==