Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966640AbcKAPAJ (ORCPT ); Tue, 1 Nov 2016 11:00:09 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:41162 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966617AbcKAPAH (ORCPT ); Tue, 1 Nov 2016 11:00:07 -0400 Subject: Re: [RFC PATCH 0/4] Clean up watchdog handlers To: Don Zickus References: <1477497743-15357-1-git-send-email-babu.moger@oracle.com> <20161031210056.GT35881@redhat.com> <16049ab0-e309-8ea7-81d4-a855c666037a@oracle.com> <20161101132011.GW35881@redhat.com> Cc: mingo@kernel.org, akpm@linux-foundation.org, ak@linux.intel.com, jkosina@suse.cz, baiyaowei@cmss.chinamobile.com, atomlin@redhat.com, uobergfe@redhat.com, tj@kernel.org, hidehiro.kawai.ez@hitachi.com, johunt@akamai.com, davem@davemloft.net, sparclinux@vger.kernel.org, bp@suse.de, bywxiaobai@163.com, cmetcalf@mellanox.com, keescook@chromium.org, ebiederm@xmission.com, huawei.libin@huawei.com, ralf@linux-mips.org, dvyukov@google.com, linux-kernel@vger.kernel.org, sam@ravnborg.org From: Babu Moger Organization: Oracle Corporation Message-ID: Date: Tue, 1 Nov 2016 09:58:02 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20161101132011.GW35881@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3438 Lines: 91 On 11/1/2016 8:20 AM, Don Zickus wrote: > On Mon, Oct 31, 2016 at 04:30:59PM -0500, Babu Moger wrote: >> On 10/31/2016 4:00 PM, Don Zickus wrote: >>> On Wed, Oct 26, 2016 at 09:02:19AM -0700, Babu Moger wrote: >>>> This is an attempt to cleanup watchdog handlers. Right now, >>>> kernel/watchdog.c implements both softlockup and hardlockup detectors. >>>> Softlockup code is generic. Hardlockup code is arch specific. Some >>>> architectures don't use hardlockup detectors. They use their own watchdog >>>> detectors. To make both these combination work, we have numerous #ifdefs >>>> in kernel/watchdog.c. >>>> >>>> We are trying here to make these handlers independent of each other. >>>> Also provide an interface for architectures to implement their own >>>> handlers. watchdog_nmi_enable and watchdog_nmi_disable will be defined >>>> as weak such that architectures can override its definitions. >>>> >>>> Thanks to Don Zickus for his suggestions. >>>> Here is the previous discussion >>>> http://www.spinics.net/lists/sparclinux/msg16441.html >>> Hi Babu, >>> >>> I finally got some cycles to poke at this today. Good work. A couple of >>> suggestions. For bisectability, I am thinking patch2 should be first and >>> patch1 and patch3 should be combined. Also watchdog_hld.c is going to need >>> up top: >>> >>> #define pr_fmt(fmt) "NMI watchdog: " fmt >>> >>> otherwise the error messages miss the header. >>> >>> Though I don't think watchdog.c and watchdog_hld.c should have the same >>> header. A good solution isn't coming to me right now. I will try to run >>> some tests on this tomorrow. >> Don, Thanks for the feedback. Let me know if you run into problems with your >> tests. > Hi Babu, > > My tests passed. I just have to tweak the expected output lines as they > constantly change. :-( > > I am going to play with different config options to see if things break from > a compile perspective. Don, Great. Thanks for the update. I had couple of compilation issues with different config options. 1. drivers/edac/edac_device.o:(.discard+0x0): multiple definition of `__pcpu_unique_hrtimer_interrupts' drivers/edac/edac_mc.o:(.discard+0x0): first defined here This was a problem with uni processor config. Thinking of moving the definition of hrtimer_interrupts and is_hardlockup into watchdog.c as softlockup code does most of the work here. 2. kernel/built-in.o: In function `watchdog_overflow_callback': >> watchdog_hld.c:(.text+0x56940): undefined reference to `sysctl_hardlockup_all_cpu_backtrace' Moved this definition to nmi.h. Will post the v2 version soon with all the comments included. Thanks Babu > >> I will start working on the comments. > Great. > > Cheers, > Don > >> Thanks >> Babu >> >>> Cheers, >>> Don >>> >>>> Babu Moger (4): >>>> watchdog: Remove hardlockup handler references >>>> watchdog: Move shared definitions to nmi.h >>>> watchdog: Move hardlockup detector in separate file >>>> sparc: Implement watchdog_nmi_enable and watchdog_nmi_disable >>>> >>>> arch/sparc/kernel/nmi.c | 44 ++++++++- >>>> include/linux/nmi.h | 19 ++++ >>>> kernel/Makefile | 1 + >>>> kernel/watchdog.c | 276 ++--------------------------------------------- >>>> kernel/watchdog_hld.c | 238 ++++++++++++++++++++++++++++++++++++++++ >>>> 5 files changed, 312 insertions(+), 266 deletions(-) >>>> create mode 100644 kernel/watchdog_hld.c >>>>