From mboxrd@z Thu Jan 1 00:00:00 1970 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 F284C4D9FD for ; Fri, 3 May 2024 16:23:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.58.86.151 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714753386; cv=none; b=pad+JdK3R7sF1gQisWeJCia6f4Y045jwKf2HtTu9torWhV20ro9FxuWvwh7s5njZnagJzXsE4lMsYRqPEdrmpAm0tzGztKm4a01sxiqdgygwwoihBRaiuc/MfTg27Sk6Q5jOPzA1yNS+iil+mWa8Xr5uEUtWqT8UI/w0rtmFh/0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714753386; c=relaxed/simple; bh=uRsf89PYPNNB+MDH2jhxz1s0c6RGa/OSvDNRlwMEnsc=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: MIME-Version:Content-Type; b=RTs89J8eZbbTpGeHDKn3ZPGWh5mVf1Zecvwjz/VA/E/sHTMCsEdqTQ/R3WpaKNWyH+SqkqvivGedZqd8iwUzAvTYWihrLWfAa2gq1hNVl1kR0wPx1sc+YpY9wErmnAMtZJ/fuszL/HTY8pfWCRxBHkfrAI8uwo15DIqC9pguV0c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ACULAB.COM; spf=pass smtp.mailfrom=aculab.com; arc=none smtp.client-ip=185.58.86.151 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-136-6zAZYStTPmWnjs5bkxLi4w-1; Fri, 03 May 2024 17:16:52 +0100 X-MC-Unique: 6zAZYStTPmWnjs5bkxLi4w-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; Fri, 3 May 2024 17:16:22 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Fri, 3 May 2024 17:16:22 +0100 From: David Laight To: 'Waiman Long' , "'linux-kernel@vger.kernel.org'" , "'peterz@infradead.org'" CC: "'mingo@redhat.com'" , "'will@kernel.org'" , "'boqun.feng@gmail.com'" , "'Linus Torvalds'" , "'virtualization@lists.linux-foundation.org'" , 'Zeng Heng' Subject: RE: [PATCH next v2 5/5] locking/osq_lock: Optimise decode_cpu() and per_cpu_ptr(). Thread-Topic: [PATCH next v2 5/5] locking/osq_lock: Optimise decode_cpu() and per_cpu_ptr(). Thread-Index: Ado8NCf0vtha6NqURtGgfE7//QxHexhPrXlAAACWziA= Date: Fri, 3 May 2024 16:16:21 +0000 Message-ID: References: <2b4e8a5816a742d2bd23fdbaa8498e80@AcuMS.aculab.com> <7c1148fe64fb46a7a81c984776cd91df@AcuMS.aculab.com> <9d4024ba-6422-4775-b934-bfa80a72a858@redhat.com> <16557e30-8353-4cd1-995b-23ec763d2b07@redhat.com> In-Reply-To: <16557e30-8353-4cd1-995b-23ec763d2b07@redhat.com> 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 RnJvbTogV2FpbWFuIExvbmcNCj4gU2VudDogMDMgTWF5IDIwMjQgMTc6MDANCj4gVG86IERhdmlk IExhaWdodCA8RGF2aWQuTGFpZ2h0QEFDVUxBQi5DT00+OyAnbGludXgta2VybmVsQHZnZXIua2Vy bmVsLm9yZycgPGxpbnV4LQ0KPiBrZXJuZWxAdmdlci5rZXJuZWwub3JnPjsgJ3BldGVyekBpbmZy YWRlYWQub3JnJyA8cGV0ZXJ6QGluZnJhZGVhZC5vcmc+DQo+IENjOiAnbWluZ29AcmVkaGF0LmNv bScgPG1pbmdvQHJlZGhhdC5jb20+OyAnd2lsbEBrZXJuZWwub3JnJyA8d2lsbEBrZXJuZWwub3Jn PjsgJ2JvcXVuLmZlbmdAZ21haWwuY29tJw0KPiA8Ym9xdW4uZmVuZ0BnbWFpbC5jb20+OyAnTGlu dXMgVG9ydmFsZHMnIDx0b3J2YWxkc0BsaW51eC1mb3VuZGF0aW9uLm9yZz47ICd2aXJ0dWFsaXph dGlvbkBsaXN0cy5saW51eC0NCj4gZm91bmRhdGlvbi5vcmcnIDx2aXJ0dWFsaXphdGlvbkBsaXN0 cy5saW51eC1mb3VuZGF0aW9uLm9yZz47ICdaZW5nIEhlbmcnIDx6ZW5naGVuZzRAaHVhd2VpLmNv bT4NCj4gU3ViamVjdDogUmU6IFtQQVRDSCBuZXh0IHYyIDUvNV0gbG9ja2luZy9vc3FfbG9jazog T3B0aW1pc2UgZGVjb2RlX2NwdSgpIGFuZCBwZXJfY3B1X3B0cigpLg0KPiANCj4gDQo+IE9uIDEy LzMxLzIzIDIzOjE0LCBXYWltYW4gTG9uZyB3cm90ZToNCj4gPg0KPiA+IE9uIDEyLzMxLzIzIDE2 OjU1LCBEYXZpZCBMYWlnaHQgd3JvdGU6DQo+ID4+IHBlcl9jcHVfcHRyKCkgaW5kZXhlcyBfX3Bl cl9jcHVfb2Zmc2V0W10gd2l0aCB0aGUgY3B1IG51bWJlci4NCj4gPj4gVGhpcyByZXF1aXJlcyB0 aGUgY3B1IG51bWJlciBiZSA2NGJpdC4NCj4gPj4gSG93ZXZlciB0aGUgdmFsdWUgaXMgb3NxX2xv Y2soKSBjb21lcyBmcm9tIGEgMzJiaXQgeGNoZygpIGFuZCB0aGVyZQ0KPiA+PiBpc24ndCBhIHdh eSBvZiB0ZWxsaW5nIGdjYyB0aGUgaGlnaCBiaXRzIGFyZSB6ZXJvICh0aGV5IGFyZSkgc28NCj4g Pj4gdGhlcmUgd2lsbCBhbHdheXMgYmUgYW4gaW5zdHJ1Y3Rpb24gdG8gY2xlYXIgdGhlIGhpZ2gg Yml0cy4NCj4gPj4NCj4gPj4gVGhlIGNwdSBudW1iZXIgaXMgYWxzbyBvZmZzZXQgYnkgb25lICh0 byBtYWtlIHRoZSBpbml0aWFsaXNlciAwKQ0KPiA+PiBJdCBzZWVtcyB0byBiZSBpbXBvc3NpYmxl IHRvIGdldCBnY2MgdG8gY29udmVydA0KPiA+PiBfX3Blcl9jcHVfb2Zmc2V0W2NwdV9wMSAtIDFd DQo+ID4+IGludG8gKF9fcGVyX2NwdV9vZmZzZXQgLSAxKVtjcHVfcDFdICh0cmFuc2ZlcnJpbmcg dGhlIG9mZnNldCB0byB0aGUNCj4gPj4gYWRkcmVzcykuDQo+ID4+DQo+ID4+IENvbnZlcnRpbmcg dGhlIGNwdSBudW1iZXIgdG8gMzJiaXQgdW5zaWduZWQgcHJpb3IgdG8gdGhlIGRlY3JlbWVudCBt ZWFucw0KPiA+PiB0aGF0IGdjYyBrbm93cyB0aGUgZGVjcmVtZW50IGhhcyBzZXQgdGhlIGhpZ2gg Yml0cyB0byB6ZXJvIGFuZCBkb2Vzbid0DQo+ID4+IGFkZCBhIHJlZ2lzdGVyLXJlZ2lzdGVyIG1v dmUgKG9yIGNsdHEpIHRvIHplcm8vc2lnbiBleHRlbmQgdGhlIHZhbHVlLg0KPiA+Pg0KPiA+PiBO b3QgbWFzc2l2ZSBidXQgc2F2ZXMgdHdvIGluc3RydWN0aW9ucy4NCj4gPj4NCj4gPj4gU2lnbmVk LW9mZi1ieTogRGF2aWQgTGFpZ2h0IDxkYXZpZC5sYWlnaHRAYWN1bGFiLmNvbT4NCj4gPj4gLS0t DQo+ID4+IMKgIGtlcm5lbC9sb2NraW5nL29zcV9sb2NrLmMgfCA2ICsrLS0tLQ0KPiA+PiDCoCAx IGZpbGUgY2hhbmdlZCwgMiBpbnNlcnRpb25zKCspLCA0IGRlbGV0aW9ucygtKQ0KPiA+Pg0KPiA+ PiBkaWZmIC0tZ2l0IGEva2VybmVsL2xvY2tpbmcvb3NxX2xvY2suYyBiL2tlcm5lbC9sb2NraW5n L29zcV9sb2NrLmMNCj4gPj4gaW5kZXggMzViYjk5ZTk2Njk3Li4zN2E0ZmE4NzI5ODkgMTAwNjQ0 DQo+ID4+IC0tLSBhL2tlcm5lbC9sb2NraW5nL29zcV9sb2NrLmMNCj4gPj4gKysrIGIva2VybmVs L2xvY2tpbmcvb3NxX2xvY2suYw0KPiA+PiBAQCAtMjksMTEgKzI5LDkgQEAgc3RhdGljIGlubGlu ZSBpbnQgZW5jb2RlX2NwdShpbnQgY3B1X25yKQ0KPiA+PiDCoMKgwqDCoMKgIHJldHVybiBjcHVf bnIgKyAxOw0KPiA+PiDCoCB9DQo+ID4+IMKgIC1zdGF0aWMgaW5saW5lIHN0cnVjdCBvcHRpbWlz dGljX3NwaW5fbm9kZSAqZGVjb2RlX2NwdShpbnQNCj4gPj4gZW5jb2RlZF9jcHVfdmFsKQ0KPiA+ PiArc3RhdGljIGlubGluZSBzdHJ1Y3Qgb3B0aW1pc3RpY19zcGluX25vZGUgKmRlY29kZV9jcHUo dW5zaWduZWQgaW50DQo+ID4+IGVuY29kZWRfY3B1X3ZhbCkNCj4gPj4gwqAgew0KPiA+PiAtwqDC oMKgIGludCBjcHVfbnIgPSBlbmNvZGVkX2NwdV92YWwgLSAxOw0KPiA+PiAtDQo+ID4+IC3CoMKg wqAgcmV0dXJuIHBlcl9jcHVfcHRyKCZvc3Ffbm9kZSwgY3B1X25yKTsNCj4gPj4gK8KgwqDCoCBy ZXR1cm4gcGVyX2NwdV9wdHIoJm9zcV9ub2RlLCBlbmNvZGVkX2NwdV92YWwgLSAxKTsNCj4gPj4g wqAgfQ0KPiA+PiDCoCDCoCAvKg0KPiA+DQo+ID4gWW91IHJlYWxseSBsaWtlIG1pY3JvLW9wdGlt aXphdGlvbi4NCj4gPg0KPiA+IEFueXdheSwNCj4gPg0KPiA+IFJldmlld2VkLWJ5OiBXYWltYW4g TG9uZyA8bG9uZ21hbkByZWRoYXQuY29tPg0KPiA+DQo+IERhdmlkLA0KPiANCj4gQ291bGQgeW91 IHJlc3BpbiB0aGUgc2VyaWVzIGJhc2VkIG9uIHRoZSBsYXRlc3QgdXBzdHJlYW0gY29kZT8NCg0K TG9va3MgbGlrZSBhIHdldCBiYW5rIGhvbGlkYXkgd2Vla2VuZC4uLi4uDQoNCglEYXZpZA0KDQot DQpSZWdpc3RlcmVkIEFkZHJlc3MgTGFrZXNpZGUsIEJyYW1sZXkgUm9hZCwgTW91bnQgRmFybSwg TWlsdG9uIEtleW5lcywgTUsxIDFQVCwgVUsNClJlZ2lzdHJhdGlvbiBObzogMTM5NzM4NiAoV2Fs ZXMpDQo=