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Date:   Fri, 19 Jan 2018 08:16:04 -0800
From:   Andi Kleen <ak@linux.intel.com>
To:     Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc:     Dave Young <dyoung@redhat.com>, pmladek@suse.com,
        sergey.senozhatsky@gmail.com, rostedt@goodmis.org,
        linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
        kexec@lists.infradead.org
Subject: Re: [PATCH] print kdump kernel loaded status in stack dump
Message-ID: <20180119161604.GH7844@tassilo.jf.intel.com>
References: <20180117045057.GA4994@dhcp-128-65.nay.redhat.com>
 <878tcvt592.fsf@linux.intel.com>
 <20180119054538.GA484@jagdpanzerIV>
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On Fri, Jan 19, 2018 at 02:45:38PM +0900, Sergey Senozhatsky wrote:
> On (01/18/18 10:02), Andi Kleen wrote:
> > Dave Young <dyoung@redhat.com> writes:
> > >  		printk("%sHardware name: %s\n",
> > >  		       log_lvl, dump_stack_arch_desc_str);
> > > +	if (kexec_crash_loaded())
> > > +		printk("%skdump kernel loaded\n", log_lvl);
> > 
> > Oops/warnings are getting longer and longer, often scrolling away
> > from the screen, and if the kernel crashes backscroll does not work
> > anymore, so precious information is lost.
> 
> true. I even ended up having a console_reflush_on_panic() function. it
> simply re-prints with a delay [so I can at least read the oops] logbuf
> entries every once in a while, staring with the first oops_in_progress
> record.

It would be better to make scrollback work even after panic (e.g. with a polled
keyboard driver)

-Andi