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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 4404BC10F27 for ; Tue, 10 Mar 2020 12:23:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1FE542464B for ; Tue, 10 Mar 2020 12:23:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726391AbgCJMXi (ORCPT ); Tue, 10 Mar 2020 08:23:38 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([207.82.80.151]:54890 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726211AbgCJMXh (ORCPT ); Tue, 10 Mar 2020 08:23:37 -0400 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-134-nZB81PfeP52EGTki-0E5KQ-1; Tue, 10 Mar 2020 12:23:34 +0000 X-MC-Unique: nZB81PfeP52EGTki-0E5KQ-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Tue, 10 Mar 2020 12:23:34 +0000 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Tue, 10 Mar 2020 12:23:34 +0000 From: David Laight To: 'Chris Wilson' , "linux-kernel@vger.kernel.org" CC: "intel-gfx@lists.freedesktop.org" , Andrew Morton , "Paul E. McKenney" , Randy Dunlap , "stable@vger.kernel.org" Subject: RE: [PATCH] list: Prevent compiler reloads inside 'safe' list iteration Thread-Topic: [PATCH] list: Prevent compiler reloads inside 'safe' list iteration Thread-Index: AQHV9r1KBrT+D4Vo2U+Op9v/Nv0od6hBsdzwgAAEwQCAAAWYAA== Date: Tue, 10 Mar 2020 12:23:34 +0000 Message-ID: <723d527a4ad349b78bf11d52eba97c0e@AcuMS.aculab.com> References: <20200310092119.14965-1-chris@chris-wilson.co.uk> <2e936d8fd2c445beb08e6dd3ee1f3891@AcuMS.aculab.com> <158384100886.16414.15741589015363013386@build.alporthouse.com> In-Reply-To: <158384100886.16414.15741589015363013386@build.alporthouse.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org RnJvbTogQ2hyaXMgV2lsc29uDQo+IFNlbnQ6IDEwIE1hcmNoIDIwMjAgMTE6NTANCj4gDQo+IFF1 b3RpbmcgRGF2aWQgTGFpZ2h0ICgyMDIwLTAzLTEwIDExOjM2OjQxKQ0KPiA+IEZyb206IENocmlz IFdpbHNvbg0KPiA+ID4gU2VudDogMTAgTWFyY2ggMjAyMCAwOToyMQ0KPiA+ID4gSW5zdHJ1Y3Qg dGhlIGNvbXBpbGVyIHRvIHJlYWQgdGhlIG5leHQgZWxlbWVudCBpbiB0aGUgbGlzdCBpdGVyYXRp b24NCj4gPiA+IG9uY2UsIGFuZCB0aGF0IGl0IGlzIG5vdCBhbGxvd2VkIHRvIHJlbG9hZCB0aGUg dmFsdWUgZnJvbSB0aGUgc3RhbGUNCj4gPiA+IGVsZW1lbnQgbGF0ZXIuIFRoaXMgaXMgaW1wb3J0 YW50IGFzIGR1cmluZyB0aGUgY291cnNlIG9mIHRoZSBzYWZlDQo+ID4gPiBpdGVyYXRpb24sIHRo ZSBzdGFsZSBlbGVtZW50IG1heSBiZSBwb2lzb25lZCAodW5iZWtub3duc3QgdG8gdGhlDQo+ID4g PiBjb21waWxlcikuDQo+ID4NCj4gPiBFaD8NCj4gPiBJIHRob3VnaHQgYW55IGZ1bmN0aW9uIGNh bGwgd2lsbCBzdG9wIHRoZSBjb21waWxlciBiZWluZyBhbGxvd2VkDQo+ID4gdG8gcmVsb2FkIHRo ZSB2YWx1ZS4NCj4gPiBUaGUgJ3NhZmUnIGxvb3AgaXRlcmF0b3JzIGFyZSBvbmx5ICdzYWZlJyBh Z2FpbnN0IGNhbGxlZA0KPiA+IGNvZGUgcmVtb3ZpbmcgdGhlIGN1cnJlbnQgaXRlbSBmcm9tIHRo ZSBsaXN0Lg0KPiA+DQo+ID4gPiBUaGlzIGhlbHBzIHByZXZlbnQga2NzYW4gd2FybmluZ3Mgb3Zl ciAndW5zYWZlJyBjb25kdWN0IGluIHJlbGVhc2luZyB0aGUNCj4gPiA+IGxpc3QgZWxlbWVudHMg ZHVyaW5nIGxpc3RfZm9yX2VhY2hfZW50cnlfc2FmZSgpIGFuZCBmcmllbmRzLg0KPiA+DQo+ID4g U291bmRzIGxpa2Uga2NzYW4gaXMgYnVnZ3kgPz8/Pw0KPiANCj4gVGhlIHdhcm5pbmcga2NzYW4g Z2F2ZSBtYWRlIHNlbnNlIChhIHN0cmFuZ2UgY2FzZSB3aGVyZSB0aGUgZW1wdHlpbmcgdGhlDQo+ IGxpc3QgZnJvbSBpbnNpZGUgdGhlIHNhZmUgaXRlcmF0b3Igd291bGQgYWxsb3cgdGhhdCBsaXN0 IHRvIGJlIHRha2VuDQo+IHVuZGVyIGEgZ2xvYmFsIG11dGV4IGFuZCBoYXZlIG9uZSBleHRyYSBy ZXF1ZXN0IGFkZGVkIHRvIGl0LiBUaGUNCj4gbGlzdF9mb3JfZWFjaF9lbnRyeV9zYWZlKCkgc2hv dWxkIGJlIG9rIGluIHRoaXMgc2NlbmFyaW8sIHNvIGxvbmcgYXMgdGhlDQo+IG5leHQgZWxlbWVu dCBpcyByZWFkIGJlZm9yZSB0aGlzIGVsZW1lbnQgaXMgZHJvcHBlZCwgYW5kIHRoZSBjb21waWxl ciBpcw0KPiBpbnN0cnVjdGVkIG5vdCB0byByZWxvYWQgdGhlIGVsZW1lbnQuDQoNCk5vcm1hbGx5 IHRoZSBsb29wIGl0ZXJhdGlvbiBjb2RlIGhhcyB0byBob2xkIHRoZSBtdXRleC4NCkkgZ3Vlc3Mg aXQgY2FuIGJlIHJlbGVhc2VkIGluc2lkZSB0aGUgbG9vcCBwcm92aWRlZCBubyBvdGhlcg0KY29k ZSBjYW4gZXZlciBkZWxldGUgZW50cmllcy4NCg0KPiBrY3NhbiBpcyBhIGxpdHRsZSBtb3JlIGlu c2lzdGVudCBvbiBoYXZpbmcgdGhhdCBhbm5vdGF0aW9uIDopDQo+IA0KPiBJbiB0aGlzIGluc3Rh bmNlIEkgd291bGQgc2F5IGl0IHdhcyBhIGZhbHNlIHBvc2l0aXZlIGZyb20ga2NzYW4sIGJ1dCBJ DQo+IGNhbiBzZWUgd2h5IGl0IHdvdWxkIGNvbXBsYWluIGFuZCBzdXNwZWN0IHRoYXQgZ2l2ZW4g YSBzdWZmaWNpZW50bHkNCj4gYWdncmVzc2l2ZSBjb21waWxlciwgd2UgbWF5IGJlIGNhdWdodCBv dXQgYnkgYSBsYXRlIHJlbG9hZCBvZiB0aGUgbmV4dA0KPiBlbGVtZW50Lg0KDQpJZiB5b3UgaGF2 ZToNCglmb3IgKDsgcDsgcCA9IG5leHQpIHsNCgkJbmV4dCA9IHAtPm5leHQ7DQoJCWV4dGVybmFs X2Z1bmN0aW9uX2NhbGwodm9pZCk7DQoJfQ0KdGhlIGNvbXBpbGVyIG11c3QgYXNzdW1lIHRoYXQg dGhlIGZ1bmN0aW9uIGNhbGwNCmNhbiBjaGFuZ2UgJ3AtPm5leHQnIGFuZCByZWFkIGl0IGJlZm9y ZSB0aGUgY2FsbC4NCg0KSXMgdGhpcyBhIGxpc3Qgd2l0aCBzdHJhbmdlIGxvY2tpbmcgcnVsZXM/ DQpUaGUgb25seSBkZWxldGVzIGFyZSBmcm9tIHdpdGhpbiB0aGUgbG9vcC4NCkFkZHMgYW5kIGRl bGV0ZXMgYXJlIGxvY2tlZC4NClRoZSBsaXN0IHRyYXZlcnNhbCBpc24ndCBsb2NrZWQuDQoNCkkg c3VzcGVjdCBrY3NhbiBibGVhdHMgYmVjYXVzZSBpdCBkb2Vzbid0IGFzc3VtZSB0aGUgY29tcGls ZXINCndpbGwgdXNlIGEgc2luZ2xlIGluc3RydWN0aW9uL21lbW9yeSBvcGVyYXRpb24gdG8gcmVh ZCBwLT5uZXh0Lg0KVGhhdCBpcyBqdXN0IHN0dXBpZC4NCg0KCURhdmlkDQoNCg0KDQoJCQ0KDQot DQpSZWdpc3RlcmVkIEFkZHJlc3MgTGFrZXNpZGUsIEJyYW1sZXkgUm9hZCwgTW91bnQgRmFybSwg TWlsdG9uIEtleW5lcywgTUsxIDFQVCwgVUsNClJlZ2lzdHJhdGlvbiBObzogMTM5NzM4NiAoV2Fs ZXMpDQo=