From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA9FBC433E0 for ; Tue, 11 Aug 2020 12:13:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C00D420756 for ; Tue, 11 Aug 2020 12:13:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728665AbgHKMMy (ORCPT ); Tue, 11 Aug 2020 08:12:54 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:3012 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728423AbgHKMLZ (ORCPT ); Tue, 11 Aug 2020 08:11:25 -0400 Received: from dggeme753-chm.china.huawei.com (unknown [172.30.72.53]) by Forcepoint Email with ESMTP id 2FEF98870F8A34B11D91; Tue, 11 Aug 2020 20:10:50 +0800 (CST) Received: from dggeme753-chm.china.huawei.com (10.3.19.99) by dggeme753-chm.china.huawei.com (10.3.19.99) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1913.5; Tue, 11 Aug 2020 20:10:49 +0800 Received: from dggeme753-chm.china.huawei.com ([10.7.64.70]) by dggeme753-chm.china.huawei.com ([10.7.64.70]) with mapi id 15.01.1913.007; Tue, 11 Aug 2020 20:10:49 +0800 From: linmiaohe To: Eric Dumazet CC: "davem@davemloft.net" , "kuba@kernel.org" , "pshelar@ovn.org" , "martin.varghese@nokia.com" , "fw@strlen.de" , "dcaratti@redhat.com" , "edumazet@google.com" , "steffen.klassert@secunet.com" , "pabeni@redhat.com" , "shmulik@metanetworks.com" , "kyk.segfault@gmail.com" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] net: eliminate meaningless memcpy to data in pskb_carve_inside_nonlinear() Thread-Topic: [PATCH] net: eliminate meaningless memcpy to data in pskb_carve_inside_nonlinear() Thread-Index: AdZv1p8z2cljr2j1QqmBFzhMwq+yDA== Date: Tue, 11 Aug 2020 12:10:49 +0000 Message-ID: <40a0b4ba22ff499686a2521998767ae5@huawei.com> Accept-Language: zh-CN, en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.174.176.252] Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 MIME-Version: 1.0 X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org RXJpYyBEdW1hemV0IDxlcmljLmR1bWF6ZXRAZ21haWwuY29tPiB3cm90ZToNCj4gT24gOC8xMC8y MCA1OjI4IEFNLCBNaWFvaGUgTGluIHdyb3RlOg0KPj4gVGhlIHNrYl9zaGFyZWRfaW5mbyBwYXJ0 IG9mIHRoZSBkYXRhIGlzIGFzc2lnbmVkIGluIHRoZSBmb2xsb3dpbmcgDQo+PiBsb29wLiBJdCBp cyBtZWFuaW5nbGVzcyB0byBkbyBhIG1lbWNweSBoZXJlLg0KPj4gDQo+DQo+UmVtaW5kZXIgOiBu ZXQtbmV4dCBpcyBDTE9TRUQuDQo+DQoNClRoYW5rcyBmb3IgeW91ciByZW1pbmQuIEkgd291bGQg d2FpdCBmb3IgaXQgb3Blbi4NCg0KPlRoaXMgaXMgbm90IGNvcnJlY3QuIFdlIHN0aWxsIGhhdmUg dG8gY29weSBfc29tZXRoaW5nXw0KPg0KPlNvbWV0aGluZyBsaWtlIDoNCj4NCj5kaWZmIC0tZ2l0 IGEvbmV0L2NvcmUvc2tidWZmLmMgYi9uZXQvY29yZS9za2J1ZmYuYyBpbmRleCAyODI4ZjZkNWJh ODk4YTVlNTBjY2NlNDU1ODliZjEzNzBlNDc0YjBmLi4xYzA1MTk0MjZjN2JhNGIwNDM3N2ZjODA1 NGM0MjIzYzEzNTg3OWFiIDEwMDY0NA0KPi0tLSBhL25ldC9jb3JlL3NrYnVmZi5jDQo+KysrIGIv bmV0L2NvcmUvc2tidWZmLmMNCj5AQCAtNTk1Myw4ICs1OTUzLDggQEAgc3RhdGljIGludCBwc2ti X2NhcnZlX2luc2lkZV9ub25saW5lYXIoc3RydWN0IHNrX2J1ZmYgKnNrYiwgY29uc3QgdTMyIG9m ZiwNCj4gICAgICAgIHNpemUgPSBTS0JfV0lUSF9PVkVSSEVBRChrc2l6ZShkYXRhKSk7DQo+IA0K PiAgICAgICAgbWVtY3B5KChzdHJ1Y3Qgc2tiX3NoYXJlZF9pbmZvICopKGRhdGEgKyBzaXplKSwN Cj4tICAgICAgICAgICAgICBza2Jfc2hpbmZvKHNrYiksIG9mZnNldG9mKHN0cnVjdCBza2Jfc2hh cmVkX2luZm8sDQo+LSAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICBmcmFn c1tza2Jfc2hpbmZvKHNrYiktPm5yX2ZyYWdzXSkpOw0KPisgICAgICAgICAgICAgIHNrYl9zaGlu Zm8oc2tiKSwgb2Zmc2V0b2Yoc3RydWN0IHNrYl9zaGFyZWRfaW5mbywgDQo+KyBmcmFnc1swXSkp Ow0KPisNCj4gICAgICAgIGlmIChza2Jfb3JwaGFuX2ZyYWdzKHNrYiwgZ2ZwX21hc2spKSB7DQo+ ICAgICAgICAgICAgICAgIGtmcmVlKGRhdGEpOw0KPiAgICAgICAgICAgICAgICByZXR1cm4gLUVO T01FTTsNCj4NCg0KVGhpcyBsb29rcyBnb29kLiBXaWxsIHNlbmQgYSBwYXRjaCB2MiBzb29uLiBN YXkgSSBhZGQgYSBzdWdnZXN0ZWQtYnkgdGFnIG9mIHlvdSA/DQpNYW55IHRoYW5rcy4NCg0K