From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754361AbbKCODA (ORCPT ); Tue, 3 Nov 2015 09:03:00 -0500 Received: from mail-db3on0093.outbound.protection.outlook.com ([157.55.234.93]:1101 "EHLO emea01-db3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751795AbbKCOCz convert rfc822-to-8bit (ORCPT ); Tue, 3 Nov 2015 09:02:55 -0500 From: Noam Camus To: Peter Zijlstra CC: "linux-snps-arc@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Tal Zilcer , Gil Fruchter , Chris Metcalf Subject: RE: [PATCH v1 16/20] ARC: [plat-eznps] Use dedicated cpu_relax() Thread-Topic: [PATCH v1 16/20] ARC: [plat-eznps] Use dedicated cpu_relax() Thread-Index: AQHRE98ZAC38OaNi/kexeLNhs+oL6Z6IeAcAgAHgDpA= Date: Tue, 3 Nov 2015 14:02:52 +0000 Message-ID: References: <1446297327-16298-1-git-send-email-noamc@ezchip.com> <1446297327-16298-17-git-send-email-noamc@ezchip.com> <20151102092142.GL17308@twins.programming.kicks-ass.net> In-Reply-To: <20151102092142.GL17308@twins.programming.kicks-ass.net> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: spf=none (sender IP is ) smtp.mailfrom=noamc@ezchip.com; x-originating-ip: [212.179.42.66] x-microsoft-exchange-diagnostics: 1;DB5PR02MB1192;5:L6I7E8h7mlLdt1dlGatN7Z0qX/GkVa/LRM+h/2mQUTDFGDErcXQgwkEOjpBK1qWMRD+JC4fWdQGLjw2P/gFFM/qHOcrdKjkAvKdzhvChhNmaOpzNWxHUDBM+kw8WJ7E47tKpzogpfeTtfQERFmS83A==;24:MPbfILnT8U6SlCDYc4edy9I8IVSDkXr+7FQ/OeJx2B6OpFkU4236A0QXis+OHaeTJ4FRnwCY8RPABTY/r4U1HruH2tDBF6UulRF0mCICfgI=;20:0pzg4ELSFsVwwM3HV70c1XsdiwyJkz1diuLoWI/ESqgUjC7Gnt4TACoZwhQpGDf7khuTuriqxVCbkM7K6wZCog== x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:DB5PR02MB1192; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:; x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(601004)(2401047)(5005006)(520078)(8121501046)(3002001)(10201501046);SRVR:DB5PR02MB1192;BCL:0;PCL:0;RULEID:;SRVR:DB5PR02MB1192; x-forefront-prvs: 0749DC2CE6 x-forefront-antispam-report: SFV:NSPM;SFS:(10009020)(6009001)(189002)(164054003)(377454003)(199003)(2900100001)(87936001)(101416001)(2950100001)(19580405001)(86362001)(77096005)(5004730100002)(5001960100002)(5007970100001)(189998001)(107886002)(110136002)(122556002)(19580395003)(66066001)(81156007)(97736004)(40100003)(10400500002)(4001430100002)(102836002)(76176999)(106356001)(106116001)(5003600100002)(92566002)(76576001)(54356999)(50986999)(105586002)(5002640100001)(33656002)(74316001)(5008740100001);DIR:OUT;SFP:1101;SCL:1;SRVR:DB5PR02MB1192;H:DB5PR02MB1141.eurprd02.prod.outlook.com;FPR:;SPF:None;PTR:InfoNoRecords;MX:1;A:1;LANG:en; spamdiagnosticoutput: 1:23 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-OriginatorOrg: ezchip.com X-MS-Exchange-CrossTenant-originalarrivaltime: 03 Nov 2015 14:02:52.5904 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 0fc16e0a-3cd3-4092-8b2f-0a42cff122c3 X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB5PR02MB1192 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra [mailto:peterz@infradead.org] Sent: Monday, November 02, 2015 11:22 AM > At which point you might want to revisit: > arch/arc/include/asm/processor.h:#define cpu_relax_lowlatency() cpu_relax() Thanks, I will define this as barrier since cpu_relax() may take out current logical CPU for many cycles.