From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rik van Riel Subject: Re: pegged softirq and NAPI race (?) Date: Tue, 18 Sep 2018 16:31:09 +0000 Message-ID: References: <6FA4008E-CEEB-4EAB-BAD8-267D41574248@fb.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Cc: netdev , Jeff Kirsher , Alexander Duyck , "michael.chan@broadcom.com" , Kernel Team To: Song Liu , Eric Dumazet Return-path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:59304 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730198AbeIRWEn (ORCPT ); Tue, 18 Sep 2018 18:04:43 -0400 In-Reply-To: <6FA4008E-CEEB-4EAB-BAD8-267D41574248@fb.com> Content-Language: en-US Content-ID: Sender: netdev-owner@vger.kernel.org List-ID: T24gVHVlLCAyMDE4LTA5LTE4IGF0IDEyOjE5IC0wNDAwLCBTb25nIExpdSB3cm90ZToNCj4gPiBP biBTZXAgMTgsIDIwMTgsIGF0IDY6NDUgQU0sIEVyaWMgRHVtYXpldCA8ZWR1bWF6ZXRAZ29vZ2xl LmNvbT4NCj4gPiB3cm90ZToNCj4gPiANCj4gPiBPbiBUdWUsIFNlcCAxOCwgMjAxOCBhdCAxOjQx IEFNIFNvbmcgTGl1IDxzb25nbGl1YnJhdmluZ0BmYi5jb20+DQo+ID4gd3JvdGU6DQo+ID4gPiAN Cj4gPiA+IFdlIGFyZSBkZWJ1Z2dpbmcgdGhpcyBpc3N1ZSB0aGF0IG5ldGNvbnNvbGUgbWVzc2Fn ZSB0cmlnZ2Vycw0KPiA+ID4gcGVnZ2VkIHNvZnRpcnENCj4gPiA+IChrc29mdGlycWQgdGFraW5n IDEwMCUgQ1BVIGZvciBtYW55IHNlY29uZHMpLiBXZSBmb3VuZCB0aGlzIGlzc3VlDQo+ID4gPiBp bg0KPiA+ID4gcHJvZHVjdGlvbiB3aXRoIGJvdGggYm54dCBhbmQgaXhnYmUsIG9uIGEgNC4xMSBi YXNlZCBrZXJuZWwuIFRoaXMNCj4gPiA+IGlzIGVhc2lseQ0KPiA+ID4gcmVwcm9kdWNpYmxlIHdp dGggaXhnYmUgb24gNC4xMSwgYW5kIGxhdGVzdCBuZXQvbmV0LW5leHQgKHNlZSBbMV0NCj4gPiA+ IGZvciBtb3JlDQo+ID4gPiBkZXRhaWwpLg0KPiA+ID4gDQo+ID4gPiBBZnRlciBkZWJ1Z2dpbmcg Zm9yIHNvbWUgdGltZSwgd2UgZm91bmQgdGhhdCB0aGlzIGlzc3VlIGlzIGxpa2VseQ0KPiA+ID4g cmVsYXRlZA0KPiA+ID4gdG8gMzllNmM4MjA4ZDdiICgibmV0OiBzb2x2ZSBhIE5BUEkgcmFjZSIp LiBBZnRlciByZXZlcnRpbmcgdGhpcw0KPiA+ID4gY29tbWl0LA0KPiA+ID4gdGhlIHN0ZXBzIGRl c2NyaWJlZCBpbiBbMV0gY2Fubm90IHJlcHJvZHVjZSB0aGUgaXNzdWUgb24gaXhnYmUuDQo+ID4g PiBSZXZlcnRpbmcNCj4gPiA+IHRoaXMgY29tbWl0IGFsc28gcmVkdWNlcyB0aGUgY2hhbmNlcyB3 ZSBoaXQgdGhlIGlzc3VlIHdpdGggYm54dA0KPiA+ID4gKGl0IHN0aWxsDQo+ID4gPiBoYXBwZW5z IHdpdGggYSBsb3dlciByYXRlKS4NCj4gPiA+IA0KPiA+ID4gSSB0cmllZCB0byBmaXggdGhpcyBp c3N1ZSB3aXRoIHJlbGF4ZWQgdmFyaWFudCAob3Igb2xkZXIgdmVyc2lvbikNCj4gPiA+IG9mDQo+ ID4gPiBuYXBpX3NjaGVkdWxlX3ByZXAoKSBpbiBuZXRwb2xsLCBqdXN0IGxpa2UgdGhlIG9uZSBv bg0KPiA+ID4gbmFwaV93YXRjaGRvZygpLg0KPiA+ID4gSG93ZXZlciwgbXkgdGVzdHMgZG8gbm90 IGFsd2F5cyBnbyBhcyBleHBlY3RlZC4NCj4gPiA+IA0KPiA+ID4gUGxlYXNlIHNoYXJlIHlvdXIg Y29tbWVudHMvc3VnZ2VzdGlvbnMgb24gd2hpY2ggZGlyZWN0aW9uIHNoYWxsDQo+ID4gPiB3ZSB0 cnkNCj4gPiA+IHRvIGZpeCB0aGlzLg0KPiA+ID4gDQo+ID4gPiBUaGFua3MgaW4gYWR2YW5jZSEN Cj4gPiA+IFNvbmcNCj4gPiA+IA0KPiA+ID4gDQo+ID4gPiBbMV0gDQo+ID4gPiBodHRwczovL3Vy bGRlZmVuc2UucHJvb2Zwb2ludC5jb20vdjIvdXJsP3U9aHR0cHMtM0FfX3d3dy5zcGluaWNzLm5l dF9saXN0c19uZXRkZXZfbXNnNTIyMzI4Lmh0bWwmZD1Ed0lCYVEmYz01VkQwUlR0TmxUaDN5Y2Q0 MWIzTVV3JnI9aTZXb2JLeGJlRzNzbHpIU0lPeFRWdFlJSnc3cWpDRTZTMHNwRFRLTC1KNCZtPWlT YU9hcGoxa3hqaEdZTGdRcjBRZDhtUUN6VmRvYm1nVDFMNEp3RnZ6eHMmcz1sQ0Vocno2d1FKVVVh Sk9reEZtdE9zekFna2YzSmg0cmVYX2kxR2JJNVJJJmU9DQo+ID4gDQo+ID4gWW91IGhhdmUgbm90 IHRyYWNlZCBpeGdiZSB0byB1bmRlcnN0YW5kIHdoeSBkcml2ZXIgaGl0cw0KPiA+ICJjbGVhbl9j b21wbGV0ZT1mYWxzZSIgYWxsIHRoZSB0aW1lID8NCj4gDQo+IFRoZSB0cmFjZSBzaG93ZWQgdGhh dCB3ZSBnb3QgImNsZWFuX2NvbXBsZXRlPWZhbHNlIiBiZWNhdXNlIA0KPiBpeGdiZV9jbGVhbl9y eF9pcnEoKSB1c2VkIGFsbCBidWRnZXQgKDY0KS4gSXQgZmVlbHMgbGlrZSB0aGUgZHJpdmVyDQo+ IGlzIHRyaWNrZWQgdG8gcHJvY2VzcyBvbGQgZGF0YSBvbiB0aGUgcnhfcmluZyBmb3Igb25lIG1v cmUgdGltZS4gDQo+IA0KPiBIYXZlIHlvdSBzZWVuIHNpbWlsYXIgaXNzdWU/DQoNCkEgcXVpY2sg cmVhZGluZyBvZiB0aGUgY29kZSBzdWdnZXN0cyB0aGF0IG1lYW5zDQpwb2xsaW5nIGNhbm5vdCBr ZWVwIHVwIHdpdGggdGhlIHJhdGUgb2YgaW5jb21pbmcNCnBhY2tldHMuDQoNClRoYXQgc2hvdWxk IG5vdCBiZSBhIHN1cnByaXNlLCBnaXZlbiB0aGF0IHBvbGxpbmcNCmFwcGVhcnMgdG8gaGFwcGVu IG9uIGp1c3Qgb25lIENQVSwgd2hpbGUgaW50ZXJydXB0DQpkcml2ZW4gcGFja2V0IGRlbGl2ZXJ5 IHdhcyBmYW5uZWQgb3V0IGFjcm9zcyBhDQpsYXJnZXIgbnVtYmVyIG9mIENQVXMuDQoNCkRvZXMg dGhlIE5BUEkgY29kZSBoYXZlIGFueSB3YXkgaW4gd2hpY2ggaXQNCnBlcmlvZGljYWxseSBmb3Jj ZS1yZXR1cm5zIHRvIElSUSBtb2RlLCBiZWNhdXNlDQptdWx0aXBsZSBDUFVzIGluIElSUSBtb2Rl IGNhbiBrZWVwIHVwIHdpdGggcGFja2V0cw0KYmV0dGVyIHRoYW4gYSBzaW5nbGUgQ1BVIGluIHBv bGxpbmcgbW9kZT8NCg0KQWx0ZXJuYXRpdmVseSwgaXMgTkFQSSB3aXRoIG11bHRpLXF1ZXVlIG5l dHdvcmsNCmFkYXB0ZXJzIHN1cHBvc2VkIHRvIGJlIHBvbGxpbmcgb24gbXVsdGlwbGUgQ1BVcywN CmJ1dCBzaW1wbHkgZmFpbGluZyB0byBkbyBzbyBpbiB0aGlzIGNhc2U/DQoNCg0K