Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752884AbdI1Lu0 (ORCPT ); Thu, 28 Sep 2017 07:50:26 -0400 Received: from omzsmtpe01.verizonbusiness.com ([199.249.25.210]:2623 "EHLO omzsmtpe01.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752577AbdI1LuY (ORCPT ); Thu, 28 Sep 2017 07:50:24 -0400 From: "Levin, Alexander (Sasha Levin)" X-Host: ranger.odc.vzwcorp.com To: Sergey Senozhatsky CC: Sasha Levin , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , "linux-kernel@vger.kernel.org List" , "pmladek@suse.com" , "sergey.senozhatsky@gmail.com" , "rostedt@goodmis.org" Subject: Re: sched: serial port lockdep warning when offlining CPUs Thread-Topic: sched: serial port lockdep warning when offlining CPUs Thread-Index: AQHTOE9JHZwnxouIqkOe3rJ/+aJblw== Date: Thu, 28 Sep 2017 11:45:30 +0000 Message-ID: <20170928114528.wilknwkyjecqrcaa@sasha-lappy> References: <20170928093847.zgcgvxb7ajiaywbr@hirez.programming.kicks-ass.net> <20170928103032.GA2380@jagdpanzerIV.localdomain> <20170928113607.GB30818@jagdpanzerIV.localdomain> In-Reply-To: <20170928113607.GB30818@jagdpanzerIV.localdomain> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: NeoMutt/20170113 (1.7.2) x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="us-ascii" Content-ID: <9F5769EDB4D7CE40A1685CECFD39C42E@vzwcorp.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v8SBoTFl017475 Content-Length: 1118 Lines: 30 On Thu, Sep 28, 2017 at 08:36:07PM +0900, Sergey Senozhatsky wrote: >On (09/28/17 19:30), Sergey Senozhatsky wrote: >> lib/ratelimit.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/lib/ratelimit.c b/lib/ratelimit.c >> index 08f8043cac61..bddc55834c2e 100644 >> --- a/lib/ratelimit.c >> +++ b/lib/ratelimit.c >> @@ -48,7 +48,8 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func) >> if (time_is_before_jiffies(rs->begin + rs->interval)) { >> if (rs->missed) { >> if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE)) { >> - pr_warn("%s: %d callbacks suppressed\n", func, rs->missed); >> + printk_deferred(KERN_WARN "%s: %d callbacks suppressed\n", > >oops... s/KERN_WARN/KERN_WARNING/ > >sorry about that. Okay, that seems to have delt with the callbacks supressed issue. I also seem to be hitting it as a result of the scheduler triggering a WARN, where print_stack_trace(), for example, just uses printk(). Now I'm not sure what's your approach here, do we keep converting printk to printk_deferred one by one until we whacked every mole? -- Thanks, Sasha