[{"id":1776907,"web_url":"http://patchwork.ozlabs.org/comment/1776907/","msgid":"<20170928092600.qvehxzikcjr65hvw@hirez.programming.kicks-ass.net>","list_archive_url":null,"date":"2017-09-28T09:26:00","subject":"Re: [PATCH 4/4] lockdep: make MAX_LOCK_DEPTH configurable from\n\tKconfig","submitter":{"id":493,"url":"http://patchwork.ozlabs.org/api/people/493/","name":"Peter Zijlstra","email":"peterz@infradead.org"},"content":"On Wed, Sep 27, 2017 at 02:42:20PM -0700, Govindarajulu Varadarajan wrote:\n> Make MAX_LOCK_DEPTH configurable. It is set to 48 right now. Number of\n> VFs under a PCI pf bus can exceed 48 and this disables lockdep.\n> \n> lockdep currently allows max of 63 held_locks.\n\nBut why a config knob? Why not just raise the number to 64\nunconditionally? And is that sufficient; you only state 48 is\ninsufficient, you don't actually state the VF limit.","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=linux-pci-owner@vger.kernel.org;\n\treceiver=)","ozlabs.org;\n\tdkim=fail reason=\"signature verification failed\" (2048-bit key;\n\tunprotected) header.d=infradead.org header.i=@infradead.org\n\theader.b=\"d3gfHNT1\"; dkim-atps=neutral"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3y2q7j6d1dz9t38\n\tfor ;\n\tThu, 28 Sep 2017 19:26:25 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1752005AbdI1J0N (ORCPT );\n\tThu, 28 Sep 2017 05:26:13 -0400","from bombadil.infradead.org ([65.50.211.133]:55295 \"EHLO\n\tbombadil.infradead.org\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1751999AbdI1J0N (ORCPT\n\t); Thu, 28 Sep 2017 05:26:13 -0400","from j217100.upc-j.chello.nl ([24.132.217.100]\n\thelo=hirez.programming.kicks-ass.net)\n\tby bombadil.infradead.org with esmtpsa (Exim 4.87 #1 (Red Hat Linux))\n\tid 1dxV51-00064Z-Cx; Thu, 28 Sep 2017 09:26:03 +0000","by hirez.programming.kicks-ass.net (Postfix, from userid 1000)\n\tid AB4592029B084; Thu, 28 Sep 2017 11:26:00 +0200 (CEST)"],"DKIM-Signature":"v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;\n\td=infradead.org; s=bombadil.20170209;\n\th=In-Reply-To:Content-Type:MIME-Version\n\t:References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:\n\tContent-Transfer-Encoding:Content-ID:Content-Description:Resent-Date:\n\tResent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:\n\tList-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive;\n\tbh=QP2/HhN70UTl3b1uYlDq6Zy7gdTGDlDsOKSMYOuiMq8=;\n\tb=d3gfHNT1KbIozTPQmcWC9KGCZ\n\tzWyY1/AGxetLFnu0U3Ls/Fs2a+QHqkN/EZjXI/BOSsAouWhA72c0XVWC3ZK1SIhYakeUk3vjaK4+p\n\tRRxaAaXiGoBNQqj+DxHAUCBD3rzaIGkF2tVZo5Xvd5NLdv6eyLP45ApbQGJqX6+3AiUuog0JFo6SM\n\tR6v+4bvyIE0TTuwSYUlQj3a4iztXilGcErGwxoBFOYwCegyVqbtp+i09PnHRja0AjF9DSThsMOYRO\n\tQMvNEaW1IFAO0OuVNDCXT32VdysALMKf7kJYxEi4JtHq4+9dXXWez73776grI1gpd0jl0ZSpPFAJb\n\thsMKKcHcg==;","Date":"Thu, 28 Sep 2017 11:26:00 +0200","From":"Peter Zijlstra ","To":"Govindarajulu Varadarajan ","Cc":"benve@cisco.com, bhelgaas@google.com, linux-pci@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org, jlbec@evilplan.org, hch@lst.de,\n\tmingo@redhat.com","Subject":"Re: [PATCH 4/4] lockdep: make MAX_LOCK_DEPTH configurable from\n\tKconfig","Message-ID":"<20170928092600.qvehxzikcjr65hvw@hirez.programming.kicks-ass.net>","References":"<20170927214220.41216-1-gvaradar@cisco.com>\n\t<20170927214220.41216-5-gvaradar@cisco.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=us-ascii","Content-Disposition":"inline","In-Reply-To":"<20170927214220.41216-5-gvaradar@cisco.com>","User-Agent":"NeoMutt/20170609 (1.8.3)","Sender":"linux-pci-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"linux-pci@vger.kernel.org"}},{"id":1777326,"web_url":"http://patchwork.ozlabs.org/comment/1777326/","msgid":"","list_archive_url":null,"date":"2017-09-28T23:51:46","subject":"Re: [PATCH 4/4] lockdep: make MAX_LOCK_DEPTH configurable from\n\tKconfig","submitter":{"id":46073,"url":"http://patchwork.ozlabs.org/api/people/46073/","name":"Govindarajulu Varadarajan","email":"gvaradar@cisco.com"},"content":"On Thu, 28 Sep 2017, Peter Zijlstra wrote:\n\n> On Wed, Sep 27, 2017 at 02:42:20PM -0700, Govindarajulu Varadarajan wrote:\n>> Make MAX_LOCK_DEPTH configurable. It is set to 48 right now. Number of\n>> VFs under a PCI pf bus can exceed 48 and this disables lockdep.\n>>\n>> lockdep currently allows max of 63 held_locks.\n>\n> But why a config knob? Why not just raise the number to 64\n> unconditionally? And is that sufficient; you only state 48 is\n> insufficient, you don't actually state the VF limit.\n>\n\nI did not want to change the default configuration for everyone.\n\nI will change it 63 unconditionally in v2 and resubmit the series.","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=linux-pci-owner@vger.kernel.org;\n\treceiver=)","ozlabs.org; dkim=pass (1024-bit key;\n\tunprotected) header.d=cisco.com header.i=@cisco.com\n\theader.b=\"OEvFa9u2\"; dkim-atps=neutral"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3y3BLN5j7lz9sP1\n\tfor ;\n\tFri, 29 Sep 2017 09:51:56 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1751339AbdI1Xvy (ORCPT );\n\tThu, 28 Sep 2017 19:51:54 -0400","from rcdn-iport-9.cisco.com ([173.37.86.80]:28172 \"EHLO\n\trcdn-iport-9.cisco.com\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1751219AbdI1Xvx (ORCPT\n\t); Thu, 28 Sep 2017 19:51:53 -0400","from alln-core-10.cisco.com ([173.36.13.132])\n\tby rcdn-iport-9.cisco.com with ESMTP/TLS/DHE-RSA-AES256-SHA;\n\t28 Sep 2017 23:51:52 +0000","from XCH-RCD-012.cisco.com (xch-rcd-012.cisco.com [173.37.102.22])\n\tby alln-core-10.cisco.com (8.14.5/8.14.5) with ESMTP id\n\tv8SNpq3f013615\n\t(version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL);\n\tThu, 28 Sep 2017 23:51:53 GMT","from cisco (10.157.132.141) by XCH-RCD-012.cisco.com\n\t(173.37.102.22) with Microsoft SMTP Server (TLS) id 15.0.1320.4;\n\tThu, 28 Sep 2017 18:51:51 -0500"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple;\n\td=cisco.com; i=@cisco.com; l=649; q=dns/txt; s=iport;\n\tt=1506642713; x=1507852313;\n\th=date:from:to:cc:subject:in-reply-to:message-id:\n\treferences:mime-version;\n\tbh=tfjUXmuXgN1Q3qtKNPt+XD7xGHEpRf3OJf0TiEUk1P8=;\n\tb=OEvFa9u2MR5V0UrleKz1pyxodtouwlg8T8KJrNgxAJJvwpyvLwr/hvu/\n\tYcxgWKF5HUfwixTH8oHzWcmX/nVNc/imWUu/xJRoys7IUVJUd2LlnwUiB\n\t2g4Gl0e91ZOaoLdp+afECDq0YyDPoFhORTZmZ2O7nCL22xJt3IXwuAkXu g=;","X-IronPort-Anti-Spam-Filtered":"true","X-IronPort-Anti-Spam-Result":"A0CoAQBRis1Z/4QNJK1dGQEBAQEBAQEBAQEBBwEBAQEBg1yBUi6dcIFUIpg9CoU7AoQlQxQBAgEBAQEBAQFrKIUYAQEBAQIBOAI/BQsLGC48GwYOiikFCKlBi0MBAQEBAQEBAQEBAQEBAQEBAQEggyuCAoFRgiCCcoRehhkFkkyOXKdmSJRYAhEZAYE5NiGBDngVhWMcggeGSYEyAYEPAQEB","X-IronPort-AV":"E=Sophos;i=\"5.42,451,1500940800\"; d=\"scan'208\";a=\"299166390\"","Date":"Thu, 28 Sep 2017 16:51:46 -0700","From":"Govindarajulu Varadarajan ","To":"Peter Zijlstra ","CC":", ,\n\t, ,\n\t, , ","Subject":"Re: [PATCH 4/4] lockdep: make MAX_LOCK_DEPTH configurable from\n\tKconfig","In-Reply-To":"<20170928092600.qvehxzikcjr65hvw@hirez.programming.kicks-ass.net>","Message-ID":"","References":"<20170927214220.41216-1-gvaradar@cisco.com>\n\t<20170927214220.41216-5-gvaradar@cisco.com>\n\t<20170928092600.qvehxzikcjr65hvw@hirez.programming.kicks-ass.net>","User-Agent":"Alpine 2.20 (LNX 67 2015-01-07)","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"US-ASCII\"; format=flowed","X-Originating-IP":"[10.157.132.141]","X-ClientProxiedBy":"xch-aln-011.cisco.com (173.36.7.21) To\n\tXCH-RCD-012.cisco.com (173.37.102.22)","Sender":"linux-pci-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"linux-pci@vger.kernel.org"}},{"id":1777639,"web_url":"http://patchwork.ozlabs.org/comment/1777639/","msgid":"<20170929162332.GA15567@bhelgaas-glaptop.roam.corp.google.com>","list_archive_url":null,"date":"2017-09-29T16:23:32","subject":"Re: [PATCH 4/4] lockdep: make MAX_LOCK_DEPTH configurable from\n\tKconfig","submitter":{"id":67298,"url":"http://patchwork.ozlabs.org/api/people/67298/","name":"Bjorn Helgaas","email":"helgaas@kernel.org"},"content":"On Thu, Sep 28, 2017 at 04:51:46PM -0700, Govindarajulu Varadarajan wrote:\n> On Thu, 28 Sep 2017, Peter Zijlstra wrote:\n> \n> >On Wed, Sep 27, 2017 at 02:42:20PM -0700, Govindarajulu Varadarajan wrote:\n> >>Make MAX_LOCK_DEPTH configurable. It is set to 48 right now. Number of\n> >>VFs under a PCI pf bus can exceed 48 and this disables lockdep.\n> >>\n> >>lockdep currently allows max of 63 held_locks.\n> >\n> >But why a config knob? Why not just raise the number to 64\n> >unconditionally? And is that sufficient; you only state 48 is\n> >insufficient, you don't actually state the VF limit.\n> >\n> \n> I did not want to change the default configuration for everyone.\n> \n> I will change it 63 unconditionally in v2 and resubmit the series.\n\nI'm not happy about having to increase MAX_LOCK_DEPTH based on a\nnumber of VFs. I haven't had time to look at the locking strategy\nyou're proposing, but it just doesn't feel right to have to take 50+\nlocks for one operation.\n\nBjorn","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=linux-pci-owner@vger.kernel.org;\n\treceiver=)","mail.kernel.org;\n\tdmarc=none (p=none dis=none) header.from=kernel.org","mail.kernel.org;\n\tspf=none smtp.mailfrom=helgaas@kernel.org"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3y3cMW6LRjz9sP1\n\tfor ;\n\tSat, 30 Sep 2017 02:24:23 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1752519AbdI2QYV (ORCPT );\n\tFri, 29 Sep 2017 12:24:21 -0400","from mail.kernel.org ([198.145.29.99]:46890 \"EHLO mail.kernel.org\"\n\trhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP\n\tid S1752296AbdI2QXe (ORCPT );\n\tFri, 29 Sep 2017 12:23:34 -0400","from localhost (unknown [69.55.156.165])\n\t(using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits))\n\t(No client certificate requested)\n\tby mail.kernel.org (Postfix) with ESMTPSA id 4F9F920C09;\n\tFri, 29 Sep 2017 16:23:33 +0000 (UTC)"],"DMARC-Filter":"OpenDMARC Filter v1.3.2 mail.kernel.org 4F9F920C09","Date":"Fri, 29 Sep 2017 11:23:32 -0500","From":"Bjorn Helgaas ","To":"Govindarajulu Varadarajan ","Cc":"Peter Zijlstra , benve@cisco.com,\n\tbhelgaas@google.com, linux-pci@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org, jlbec@evilplan.org, hch@lst.de,\n\tmingo@redhat.com","Subject":"Re: [PATCH 4/4] lockdep: make MAX_LOCK_DEPTH configurable from\n\tKconfig","Message-ID":"<20170929162332.GA15567@bhelgaas-glaptop.roam.corp.google.com>","References":"<20170927214220.41216-1-gvaradar@cisco.com>\n\t<20170927214220.41216-5-gvaradar@cisco.com>\n\t<20170928092600.qvehxzikcjr65hvw@hirez.programming.kicks-ass.net>\n\t","MIME-Version":"1.0","Content-Type":"text/plain; charset=us-ascii","Content-Disposition":"inline","In-Reply-To":"","User-Agent":"Mutt/1.5.21 (2010-09-15)","Sender":"linux-pci-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"linux-pci@vger.kernel.org"}},{"id":1777874,"web_url":"http://patchwork.ozlabs.org/comment/1777874/","msgid":"","list_archive_url":null,"date":"2017-09-30T06:03:04","subject":"Re: [PATCH 4/4] lockdep: make MAX_LOCK_DEPTH configurable from\n\tKconfig","submitter":{"id":46073,"url":"http://patchwork.ozlabs.org/api/people/46073/","name":"Govindarajulu Varadarajan","email":"gvaradar@cisco.com"},"content":"On Fri, 29 Sep 2017, Bjorn Helgaas wrote:\n\n> On Thu, Sep 28, 2017 at 04:51:46PM -0700, Govindarajulu Varadarajan wrote:\n>> On Thu, 28 Sep 2017, Peter Zijlstra wrote:\n>>\n>>> On Wed, Sep 27, 2017 at 02:42:20PM -0700, Govindarajulu Varadarajan wrote:\n>>>> Make MAX_LOCK_DEPTH configurable. It is set to 48 right now. Number of\n>>>> VFs under a PCI pf bus can exceed 48 and this disables lockdep.\n>>>>\n>>>> lockdep currently allows max of 63 held_locks.\n>>>\n>>> But why a config knob? Why not just raise the number to 64\n>>> unconditionally? And is that sufficient; you only state 48 is\n>>> insufficient, you don't actually state the VF limit.\n>>>\n>>\n>> I did not want to change the default configuration for everyone.\n>>\n>> I will change it 63 unconditionally in v2 and resubmit the series.\n>\n> I'm not happy about having to increase MAX_LOCK_DEPTH based on a\n> number of VFs. I haven't had time to look at the locking strategy\n> you're proposing, but it just doesn't feel right to have to take 50+\n> locks for one operation.\n\nI agree. I have sent V2 where we dont lock 50+ device_lock. Please have a look.","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=linux-pci-owner@vger.kernel.org;\n\treceiver=)","ozlabs.org; dkim=pass (1024-bit key;\n\tunprotected) header.d=cisco.com header.i=@cisco.com\n\theader.b=\"JoA87eM+\"; dkim-atps=neutral"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3y3yXR6JCfz9t4r\n\tfor ;\n\tSat, 30 Sep 2017 16:03:19 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1750847AbdI3GDS (ORCPT );\n\tSat, 30 Sep 2017 02:03:18 -0400","from alln-iport-1.cisco.com ([173.37.142.88]:46945 \"EHLO\n\talln-iport-1.cisco.com\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1750724AbdI3GDR (ORCPT\n\t); Sat, 30 Sep 2017 02:03:17 -0400","from rcdn-core-10.cisco.com ([173.37.93.146])\n\tby alln-iport-1.cisco.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384;\n\t30 Sep 2017 06:03:16 +0000","from XCH-RCD-012.cisco.com (xch-rcd-012.cisco.com [173.37.102.22])\n\tby rcdn-core-10.cisco.com (8.14.5/8.14.5) with ESMTP id\n\tv8U63GGG017489\n\t(version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL);\n\tSat, 30 Sep 2017 06:03:16 GMT","from cisco (10.24.76.29) by XCH-RCD-012.cisco.com (173.37.102.22)\n\twith Microsoft SMTP Server (TLS) id 15.0.1320.4;\n\tSat, 30 Sep 2017 01:03:15 -0500"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple;\n\td=cisco.com; i=@cisco.com; l=1131; q=dns/txt; s=iport;\n\tt=1506751397; x=1507960997;\n\th=date:from:to:cc:subject:in-reply-to:message-id:\n\treferences:mime-version;\n\tbh=Dhpg1F/KWPTk1d9nYURiy4g0FU8blAZgiOwMA5ucasQ=;\n\tb=JoA87eM+ncToS5YtFfpOrs1SsWmYae3kVJjZ7DwgiSNo9FcUj4X2nTEk\n\tUUUkfJ0mUowxrLiO9JD1sKHb7WhV0N8RcfwV/A+bBLiTEpfg69kGmhFua\n\tymMOLROQLVkEnFiurASgw+8R7nqnYOHEu4WVtExj45a+J5mBIzaoX1bSj U=;","X-IronPort-Anti-Spam-Filtered":"true","X-IronPort-Anti-Spam-Result":"A0C9AgDUMs9Z/5JdJa1cGQEBAQEBAQEBAQEBBwEBAQEBg1yBUi6ddYFUIpg+CoU7AoQzVwECAQEBAQECayiFGAEBAQECATgCPwULCxguPBsGDoopBQioQ4tDAQEBAQEBAQEBAQEBAQEBAQEBAR+DLYICgVGCIIJyhF6GGQWST45glniFbosFSJRbAhEZAYE5V4EOeBWFYxyCB4drgTIBgQ8BAQE","X-IronPort-AV":"E=Sophos;i=\"5.42,456,1500940800\"; d=\"scan'208\";a=\"10727420\"","Date":"Fri, 29 Sep 2017 23:03:04 -0700","From":"Govindarajulu Varadarajan ","To":"Bjorn Helgaas ","CC":"Peter Zijlstra , ,\n\t, ,\n\t, , ,\n\t","Subject":"Re: [PATCH 4/4] lockdep: make MAX_LOCK_DEPTH configurable from\n\tKconfig","In-Reply-To":"<20170929162332.GA15567@bhelgaas-glaptop.roam.corp.google.com>","Message-ID":"","References":"<20170927214220.41216-1-gvaradar@cisco.com>\n\t<20170927214220.41216-5-gvaradar@cisco.com>\n\t<20170928092600.qvehxzikcjr65hvw@hirez.programming.kicks-ass.net>\n\t\n\t<20170929162332.GA15567@bhelgaas-glaptop.roam.corp.google.com>","User-Agent":"Alpine 2.20 (LNX 67 2015-01-07)","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"US-ASCII\"; format=flowed","X-Originating-IP":"[10.24.76.29]","X-ClientProxiedBy":"xch-aln-002.cisco.com (173.36.7.12) To\n\tXCH-RCD-012.cisco.com (173.37.102.22)","Sender":"linux-pci-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"linux-pci@vger.kernel.org"}}]