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[2604:1380:45e3:2400::1]) by mx.google.com with ESMTPS id k2-20020a170902c40200b001d3fbe6900dsi17501301plk.622.2023.12.31.03.56.37 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 31 Dec 2023 03:56:37 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-13699-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel+bounces-13699-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-13699-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=aculab.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sv.mirrors.kernel.org (Postfix) with ESMTPS id B7E17281BAE for ; Sun, 31 Dec 2023 11:56:36 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 640028F63; Sun, 31 Dec 2023 11:56:31 +0000 (UTC) X-Original-To: linux-kernel@vger.kernel.org Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2838F8F40 for ; Sun, 31 Dec 2023 11:56:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ACULAB.COM Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=aculab.com Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-281-aBBp7YTVPSWzhyLiFTN6yg-1; Sun, 31 Dec 2023 11:56:25 +0000 X-MC-Unique: aBBp7YTVPSWzhyLiFTN6yg-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Sun, 31 Dec 2023 11:56:05 +0000 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Sun, 31 Dec 2023 11:56:05 +0000 From: David Laight To: 'Linus Torvalds' CC: "linux-kernel@vger.kernel.org" , "peterz@infradead.org" , "longman@redhat.com" , "mingo@redhat.com" , "will@kernel.org" , "boqun.feng@gmail.com" , "xinhui.pan@linux.vnet.ibm.com" , "virtualization@lists.linux-foundation.org" , Zeng Heng Subject: RE: [PATCH next 4/5] locking/osq_lock: Optimise per-cpu data accesses. Thread-Topic: [PATCH next 4/5] locking/osq_lock: Optimise per-cpu data accesses. Thread-Index: Ado6mZUJWFdx4PkETd+mn/PWVjPd0AAyXXgoAB7ieYA= Date: Sun, 31 Dec 2023 11:56:05 +0000 Message-ID: <5cff1ac6581142228886f78d54d836cf@AcuMS.aculab.com> References: <73a4b31c9c874081baabad9e5f2e5204@AcuMS.aculab.com> In-Reply-To: Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 RnJvbTogTGludXMgVG9ydmFsZHMNCj4gU2VudDogMzAgRGVjZW1iZXIgMjAyMyAyMDo1OQ0KPiAN Cj4gT24gU2F0LCAzMCBEZWMgMjAyMyBhdCAxMjo0MSwgTGludXMgVG9ydmFsZHMNCj4gPHRvcnZh bGRzQGxpbnV4LWZvdW5kYXRpb24ub3JnPiB3cm90ZToNCj4gPg0KPiA+IFVOVEVTVEVEIHBhdGNo IHRvIGp1c3QgZG8gdGhlICJ0aGlzX2NwdV93cml0ZSgpIiBwYXJ0cyBhdHRhY2hlZC4NCj4gPiBB Z2Fpbiwgbm90ZSBob3cgd2UgZG8gZW5kIHVwIGRvaW5nIHRoYXQgdGhpc19jcHVfcHRyIGNvbnZl cnNpb24gbGF0ZXINCj4gPiBhbnl3YXksIGJ1dCBhdCBsZWFzdCBpdCdzIG9mZiB0aGUgY3JpdGlj YWwgcGF0aC4NCj4gDQo+IEFsc28gbm90ZSB0aGF0IHdoaWxlICd0aGlzX2NwdV9wdHIoKScgZG9l c24ndCBleGFjdGx5IGdlbmVyYXRlIGxvdmVseQ0KPiBjb2RlLCBpdCByZWFsbHkgaXMgc3RpbGwg YmV0dGVyIHRoYW4gY2FjaGluZyBhIHZhbHVlIGluIG1lbW9yeS4NCj4gDQo+IEF0IGxlYXN0IHRo ZSBtZW1vcnkgbG9jYXRpb24gdGhhdCAndGhpc19jcHVfcHRyKCknIGFjY2Vzc2VzIGlzDQo+IHNs aWdodGx5IG1vcmUgbGlrZWx5IHRvIGJlIGhvdCAoYW5kIGlzIHJpZ2h0IG5leHQgdG8gdGhlIGNw dSBudW1iZXIsDQo+IGlpcmMpLg0KDQpJIHdhcyBvbmx5IGdvaW5nIHRvIGFjY2VzcyB0aGUgJ3Nl bGYnIGZpZWxkIGluIGNvZGUgdGhhdCByZXF1aXJlZA0KdGhlICdub2RlJyBjYWNoZSBsaW5lIGJl IHByZXNlbnQuDQoNCj4gDQo+IFRoYXQgc2FpZCwgSSB0aGluayB3ZSBzaG91bGQgZml4IHRoaXNf Y3B1X3B0cigpIHRvIG5vdCBldmVyIGdlbmVyYXRlDQo+IHRoYXQgZGlzZ3VzdGluZyBjbHRxIGp1 c3QgYmVjYXVzZSB0aGUgY3B1IHBvaW50ZXIgaGFzIHRoZSB3cm9uZw0KPiBzaWduZWRuZXNzLiBJ IGRvbid0IHF1aXRlIGtub3cgaG93IHRvIGRvIGl0LCBidXQgdGhpczoNCj4gDQo+ICAgLSNkZWZp bmUgcGVyX2NwdV9vZmZzZXQoeCkgKF9fcGVyX2NwdV9vZmZzZXRbeF0pDQo+ICAgKyNkZWZpbmUg cGVyX2NwdV9vZmZzZXQoeCkgKF9fcGVyX2NwdV9vZmZzZXRbKHVuc2lnbmVkKSh4KV0pDQo+IA0K PiBhdCBsZWFzdCBoZWxwcyBhICpiaXQqLiBJdCBnZXRzIHJpZCBvZiB0aGUgY2x0cSwgYXQgbGVh c3QsIGJ1dCBpZg0KPiBzb21lYm9keSBhY3R1YWxseSBwYXNzZXMgaW4gYW4gJ3Vuc2lnbmVkIGxv bmcnIGNwdWlkLCBpdCB3b3VsZCBjYXVzZQ0KPiBhbiB1bm5lY2Vzc2FyeSB0cnVuY2F0aW9uLg0K DQpEb2luZyB0aGUgY29udmVyc2lvbiB1c2luZyBhcml0aG1ldGljIG1pZ2h0IGhlbHAsIHNvOg0K CQlfX3Blcl9jcHVfb2Zmc2V0Wyh4KSArIDB1XQ0KDQo+IEFuZCBnY2Mgc3RpbGwgZ2VuZXJhdGVz DQo+IA0KPiAgICAgICAgIHN1YmwgICAgJDEsICVlYXggICAgICAgICMsIGNwdV9ucg0KPiAgICAg ICAgIGFkZHEgICAgX19wZXJfY3B1X29mZnNldCgsJXJheCw4KSwgJXJjeA0KPiANCj4gaW5zdGVh ZCBvZiBqdXN0IGRvaW5nDQo+IA0KPiAgICAgICAgIGFkZHEgICAgX19wZXJfY3B1X29mZnNldC04 KCwlcmF4LDgpLCAlcmN4DQo+IA0KPiBiZWNhdXNlIGl0IHN0aWxsIG5lZWRzIHRvIGNsZWFyIHRo ZSB1cHBlciAzMiBiaXRzIGFuZCBkb2Vzbid0IGtub3cNCj4gdGhhdCB0aGUgJ3hjaGcoKScgYWxy ZWFkeSBkaWQgdGhhdC4NCg0KTm90IG9ubHkgdGhhdCwgeW91IG5lZWQgdG8gZG8gdGhlICdzdWJs JyBhZnRlciBjb252ZXJ0aW5nIHRvIDY0IGJpdHMuDQpPdGhlcndpc2UgdGhlIHdyb25nIGxvY2F0 aW9uIGlzIHJlYWQgd2VyZSBjcHVfbnIgdG8gYmUgemVyby4NCkkndmUgdHJpZWQgdGhhdCAtIGJ1 dCBpdCBzdGlsbCBmYWlsZWQuDQoNCj4gT2ggd2VsbC4gSSBndWVzcyBldmVuIHdpdGhvdXQgdGhl IC0xLysxIGdhbWVzIGJ5IHRoZSBPU1EgY29kZSwgd2UNCj4gd291bGQgc3RpbGwgZW5kIHVwIHdp dGggYSAibW92bCIganVzdCB0byBkbyB0aGF0IHVwcGVyIGJpdHMgY2xlYXJpbmcNCj4gdGhhdCB0 aGUgY29tcGlsZXIgZG9lc24ndCBrbm93IGlzIHVubmVjZXNzYXJ5Lg0KPiANCj4gSSBkb24ndCB0 aGluayB3ZSBoYXZlIGFueSByZWFzb25hYmxlIHdheSB0byB0ZWxsIHRoZSBjb21waWxlciB0aGF0 IHRoZQ0KPiByZWdpc3RlciBvdXRwdXQgb2Ygb3VyIHhjaGcoKSBpbmxpbmUgYXNtIGhhcyB0aGUg dXBwZXIgMzIgYml0cyBjbGVhci4NCg0KSXQgY291bGQgYmUgZG9uZSBmb3IgYSAzMmJpdCB1bnNp Z25lZCB4Y2hnKCkgLSBqdXN0IG1ha2UgdGhlIHJldHVybg0KdHlwZSB1bnNpZ25lZCA2NGJpdC4N CkJ1dCB0aGF0IHdvbid0IHdvcmsgZm9yIHRoZSBzaWduZWQgZXhjaGFuZ2UgLSBhbmQgJ2F0b21p Y190JyBpcyBzaWduZWQuDQpPVE9IIEknZCBndWVzcyB0aGlzIGNvZGUgY291bGQgdXNlICd1bnNp Z25lZCBpbnQnIGluc3RlYWQgb2YgYXRvbWljX3Q/DQoNCglEYXZpZA0KDQotDQpSZWdpc3RlcmVk IEFkZHJlc3MgTGFrZXNpZGUsIEJyYW1sZXkgUm9hZCwgTW91bnQgRmFybSwgTWlsdG9uIEtleW5l cywgTUsxIDFQVCwgVUsNClJlZ2lzdHJhdGlvbiBObzogMTM5NzM4NiAoV2FsZXMpDQo=