From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 0B326C7D for ; Wed, 5 Jul 2017 15:43:20 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 102A4A7 for ; Wed, 5 Jul 2017 15:43:18 +0000 (UTC) Date: Wed, 5 Jul 2017 11:43:16 -0400 From: Steven Rostedt To: James Bottomley Message-ID: <20170705114316.424a9e28@gandalf.local.home> In-Reply-To: <1499268748.3668.20.camel@HansenPartnership.com> References: <576cea07-770a-4864-c3f5-0832ff211e94@leemhuis.info> <20170703123025.7479702e@gandalf.local.home> <20170705084528.67499f8c@gandalf.local.home> <4080ecc7-1aa8-2940-f230-1b79d656cdb4@redhat.com> <20170705092757.63dc2328@gandalf.local.home> <20170705140607.GA30187@kroah.com> <20170705143341.oees22k2snhtmkxo@sirena.org.uk> <20170705103658.226099c6@gandalf.local.home> <1499266228.3668.10.camel@HansenPartnership.com> <20170705105651.5da9c969@gandalf.local.home> <1499267389.3668.16.camel@HansenPartnership.com> <20170705112047.23ee09f6@gandalf.local.home> <1499268748.3668.20.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: Carlos O'Donell , linux-api@vger.kernel.org, Shuah Khan , ksummit-discuss@lists.linuxfoundation.org, Thorsten Leemhuis Subject: Re: [Ksummit-discuss] [MAINTAINERS SUMMIT] & [TECH TOPIC] Improve regression tracking List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 05 Jul 2017 08:32:28 -0700 James Bottomley wrote: > > openSuSE has it enabled? I hope not for its production config, as > > lockdep has a huge performance penalty. =20 >=20 > Then, surely, it's the last thing we want when tracking down race > conditgions since it will alter timings dramatically. It's to be run when you want to make sure locking order is at least not an issue. And it's not about running when tracking down race conditions, its to be run when developing new code. >=20 > > I'm thinking you don't have it enabled. What config are you looking > > at? The actual config that does the testing of locks is > > CONFIG_PROVE_LOCKING, which selects LOCKDEP to be compiled in. =20 >=20 > This is what it has: >=20 > jejb@jarvis:~/git/linux-build> grep LOCKDEP /boot/config-4.4.73-18.17-def= ault=C2=A0 > CONFIG_LOCKDEP_SUPPORT=3Dy That means your architecture supports it, it's not enabled. -- Steve From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [Ksummit-discuss] [MAINTAINERS SUMMIT] & [TECH TOPIC] Improve regression tracking Date: Wed, 5 Jul 2017 11:43:16 -0400 Message-ID: <20170705114316.424a9e28@gandalf.local.home> References: <576cea07-770a-4864-c3f5-0832ff211e94@leemhuis.info> <20170703123025.7479702e@gandalf.local.home> <20170705084528.67499f8c@gandalf.local.home> <4080ecc7-1aa8-2940-f230-1b79d656cdb4@redhat.com> <20170705092757.63dc2328@gandalf.local.home> <20170705140607.GA30187@kroah.com> <20170705143341.oees22k2snhtmkxo@sirena.org.uk> <20170705103658.226099c6@gandalf.local.home> <1499266228.3668.10.camel@HansenPartnership.com> <20170705105651.5da9c969@gandalf.local.home> <1499267389.3668.16.camel@HansenPartnership.com> <20170705112047.23ee09f6@gandalf.local.home> <1499268748.3668.20.camel@HansenPartnership.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <1499268748.3668.20.camel-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: James Bottomley Cc: Carlos O'Donell , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Shuah Khan , ksummit-discuss-cunTk1MwBs98uUxBSJOaYoYkZiVZrdSR2LY78lusg7I@public.gmane.org, Thorsten Leemhuis List-Id: linux-api@vger.kernel.org On Wed, 05 Jul 2017 08:32:28 -0700 James Bottomley wrote: > > openSuSE has it enabled? I hope not for its production config, as > > lockdep has a huge performance penalty. > > Then, surely, it's the last thing we want when tracking down race > conditgions since it will alter timings dramatically. It's to be run when you want to make sure locking order is at least not an issue. And it's not about running when tracking down race conditions, its to be run when developing new code. > > > I'm thinking you don't have it enabled. What config are you looking > > at? The actual config that does the testing of locks is > > CONFIG_PROVE_LOCKING, which selects LOCKDEP to be compiled in. > > This is what it has: > > jejb@jarvis:~/git/linux-build> grep LOCKDEP /boot/config-4.4.73-18.17-default  > CONFIG_LOCKDEP_SUPPORT=y That means your architecture supports it, it's not enabled. -- Steve