From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=cMRp=OU=gmail.com=sergey.senozhatsky.work@kernel.org>
Date: Tue, 11 Dec 2018 18:08:29 +0900
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Feng Tang <feng.tang@intel.com>, Peter Zijlstra <peterz@infradead.org>,
	Petr Mladek <pmladek@suse.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Frederic Weisbecker <fweisbec@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	akpm@linux-foundation.org, bp@suse.de, keescook@chromium.org,
	mm-commits@vger.kernel.org, sergey.senozhatsky@gmail.com,
	stable@vger.kernel.org, Sasha Levin <sashal@kernel.org>,
	Andi Kleen <ak@linux.intel.com>, linux-kernel@vger.kernel.org
Subject: Re: + panic-avoid-the-extra-noise-dmesg.patch added to -mm tree
Message-ID: <20181211090829.GA471@jagdpanzerIV>
References: <20181205025728.GC503@jagdpanzerIV>
 <20181205052912.GA423@jagdpanzerIV>
 <20181205080044.GA11190@jagdpanzerIV>
 <20181205154620.4dqtledc2duhrp2c@shbuild888>
 <20181206035825.jz2bfh3errj23rjq@shbuild888>
 <20181207095004.GB3729@jagdpanzerIV>
 <20181210094554.z5n7dmkrnlcpygg4@shbuild888>
 <20181210155705.qowbi7xvszzfonzk@pathway.suse.cz>
 <20181211080743.GB521@jagdpanzerIV>
 <20181211083207.b5mbbuohsiorqnoj@shbuild888>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20181211083207.b5mbbuohsiorqnoj@shbuild888>
List-ID: <stable.vger.kernel.org>

Adding Frederic,

https://lkml.org/lkml/2018/10/11/304


On (12/11/18 16:32), Feng Tang wrote:
> Here is the v1 patch: https://lkml.org/lkml/2018/10/11/304
>
> And actually no one ruled out the v1 patch :), I don't have HW of other
> archs like arm/ppc, so I just read some of the arch code, and found
> most of them use the similar flow like x86, that's why I chosed to
> finding a soluton inside panic.c itself.

Interesting. So if the problem is that we need to clear cpu bit in
several cpumaks (e.g. nohz.idle_cpus_mask) when we stop_this_cpu(),
then I'd say let's clear cpumasks which are needed to be clear (doing
some of the things which sched_cpu_dying() does, except that we need
it on !CONFIG_HOTPLUG_CPU systems too). The idea of notifiers also looks
interesting.


x86 and sched gurus, can you please help?

	-ss