From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.windriver.com (mail.windriver.com [147.11.1.11]) (using TLSv1.1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 02191211D2317 for ; Mon, 18 Mar 2019 04:49:09 -0700 (PDT) From: "Liu, Yongxin" Subject: RE: [PATCH RT] nvdimm: make lane acquirement RT aware Date: Mon, 18 Mar 2019 11:48:28 +0000 Message-ID: <597B109EC20B76429F71A8A97770610D12A649C1@ALA-MBD.corp.ad.wrs.com> References: <20190306095709.23138-1-yongxin.liu@windriver.com> <20190307143344.ytsnbmot5tjzjhip@linutronix.de> <597B109EC20B76429F71A8A97770610D12A52669@ALA-MBD.corp.ad.wrs.com> <20190308094131.ge4wbsvz4p6xikdf@linutronix.de> <597B109EC20B76429F71A8A97770610D12A5643B@ALA-MBD.corp.ad.wrs.com> <20190315164236.rzbwe7reeprjv3um@linutronix.de> <597B109EC20B76429F71A8A97770610D12A63C81@ALA-MBD.corp.ad.wrs.com> <20190318114017.tazjaegln2obt3zg@linutronix.de> In-Reply-To: <20190318114017.tazjaegln2obt3zg@linutronix.de> Content-Language: en-US MIME-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Sebastian Andrzej Siewior Cc: "linux-rt-users@vger.kernel.org" , "linux-nvdimm@lists.01.org" , "linux-kernel@vger.kernel.org" , "rostedt@goodmis.org" , "Gortmaker, Paul , tglx@linutronix.de" List-ID: > -----Original Message----- > From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel- > owner@vger.kernel.org] On Behalf Of Sebastian Andrzej Siewior > Sent: Monday, March 18, 2019 19:40 > To: Liu, Yongxin > Cc: linux-kernel@vger.kernel.org; linux-rt-users@vger.kernel.org; > tglx@linutronix.de; rostedt@goodmis.org; dan.j.williams@intel.com; > pagupta@redhat.com; Gortmaker, Paul; linux-nvdimm@lists.01.org > Subject: Re: [PATCH RT] nvdimm: make lane acquirement RT aware > > On 2019-03-18 01:41:10 [+0000], Liu, Yongxin wrote: > > > > Consider the recursive call to nd_region_acquire_lane() in the > following situation. > > Will there be a dead lock? > > > > > > Thread A Thread B > > | | > > | | > > CPU 1 CPU 2 > > | | > > | | > > get lock for Lane 1 get lock for Lane 2 > > | | > > | | > > migrate to CPU 2 migrate to CPU 1 > > | | > > | | > > wait lock for Lane 2 wait lock for Lane 1 > > | | > > | | > > _____________________________ > > | > > dead lock ? > > Bummer. That would dead lock indeed. > Is it easily possible to recognize the recursive case? Not easily. I don't have test case for recursive call. For now, just code analysis. Yongxin > > > > Thanks, > > Yognxin > > Sebastian _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm 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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 4306CC10F00 for ; Mon, 18 Mar 2019 11:49:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D97720854 for ; Mon, 18 Mar 2019 11:49:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727220AbfCRLtR (ORCPT ); Mon, 18 Mar 2019 07:49:17 -0400 Received: from mail.windriver.com ([147.11.1.11]:34792 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726915AbfCRLtQ (ORCPT ); Mon, 18 Mar 2019 07:49:16 -0400 Received: from ALA-HCA.corp.ad.wrs.com ([147.11.189.40]) by mail.windriver.com (8.15.2/8.15.1) with ESMTPS id x2IBmTqF028694 (version=TLSv1 cipher=AES128-SHA bits=128 verify=FAIL); Mon, 18 Mar 2019 04:48:29 -0700 (PDT) Received: from ALA-MBD.corp.ad.wrs.com ([169.254.3.68]) by ALA-HCA.corp.ad.wrs.com ([147.11.189.40]) with mapi id 14.03.0439.000; Mon, 18 Mar 2019 04:48:28 -0700 From: "Liu, Yongxin" To: Sebastian Andrzej Siewior CC: "linux-kernel@vger.kernel.org" , "linux-rt-users@vger.kernel.org" , "tglx@linutronix.de" , "rostedt@goodmis.org" , "dan.j.williams@intel.com" , "pagupta@redhat.com" , "Gortmaker, Paul" , "linux-nvdimm@lists.01.org" Subject: RE: [PATCH RT] nvdimm: make lane acquirement RT aware Thread-Topic: [PATCH RT] nvdimm: make lane acquirement RT aware Thread-Index: AQHU1AQaa42orSwEx0mmBzBs0WZNkaYAw5wAgAAVVLCAAStcgIADmlcQgAfK3QCAA0RWUIABHjGA//+MC+A= Date: Mon, 18 Mar 2019 11:48:28 +0000 Message-ID: <597B109EC20B76429F71A8A97770610D12A649C1@ALA-MBD.corp.ad.wrs.com> References: <20190306095709.23138-1-yongxin.liu@windriver.com> <20190307143344.ytsnbmot5tjzjhip@linutronix.de> <597B109EC20B76429F71A8A97770610D12A52669@ALA-MBD.corp.ad.wrs.com> <20190308094131.ge4wbsvz4p6xikdf@linutronix.de> <597B109EC20B76429F71A8A97770610D12A5643B@ALA-MBD.corp.ad.wrs.com> <20190315164236.rzbwe7reeprjv3um@linutronix.de> <597B109EC20B76429F71A8A97770610D12A63C81@ALA-MBD.corp.ad.wrs.com> <20190318114017.tazjaegln2obt3zg@linutronix.de> In-Reply-To: <20190318114017.tazjaegln2obt3zg@linutronix.de> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [128.224.162.171] Content-Type: text/plain; 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