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From: John Ogness <john.ogness@linutronix.de>
To: Petr Mladek <pmladek@suse.com>
Cc: lijiang <lijiang@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andrea Parri <parri.andrea@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	kexec@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: crashdump: Re: [PATCH 2/2] printk: use the lockless ringbuffer
Date: Mon, 17 Feb 2020 17:14:22 +0100	[thread overview]
Message-ID: <87zhdh9oo1.fsf@linutronix.de> (raw)
In-Reply-To: <20200217154026.7x2xyrklprgql4if@pathway.suse.cz> (Petr Mladek's message of "Mon, 17 Feb 2020 16:40:26 +0100")

On 2020-02-17, Petr Mladek <pmladek@suse.com> wrote:
>>> Should the "prb"(printk tb static) symbol be exported into
>>> vmcoreinfo?  Otherwise, do you happen to know how to walk through
>>> the log_buf and get all kernel logs from vmcore?
>> 
>> You are correct. This will need to be exported as well so that the
>> descriptors can be accessed. (log_buf is only the pure human-readable
>> text.) I am currently hacking the crash tool to see exactly what
>> needs to be made available in order to access all the data of the
>> ringbuffer.
>
> I am not sure which parts you are working on. Are you going to provide
> also patch for makedumpfile, please?

I'm working on crash first. makedumpfile is on my list as well.

> I get the following failure when creating the crashdump using:
>
>     echo c >/proc/sysrq-trigger
>
>
> The kernel version is not supported.
> The makedumpfile operation may be incomplete.
> dump_dmesg: Can't find variable-length record symbols
> makedumpfile Failed.
> Running makedumpfile --dump-dmesg /proc/vmcore failed (1).

Yes, the symbols have changed (and some are missing). I will get this
sorted out for v2. And I will provide some heavily hacked code for crash
and makedumpfile to show that the necessary symbols are there and it
works.

John Ogness

  reply	other threads:[~2020-02-17 16:14 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-28 16:19 [PATCH 0/2] printk: replace ringbuffer John Ogness
2020-01-28 16:19 ` [PATCH 1/2] printk: add lockless buffer John Ogness
2020-01-29  3:53   ` Steven Rostedt
2020-02-21 11:54   ` more barriers: " Petr Mladek
2020-02-27 12:04     ` John Ogness
2020-03-04 15:08       ` Petr Mladek
2020-03-13 10:13         ` John Ogness
2020-02-21 12:05   ` misc nits " Petr Mladek
2020-03-02 10:38     ` John Ogness
2020-03-02 12:17       ` Joe Perches
2020-03-02 12:32       ` Petr Mladek
2020-03-02 13:43         ` John Ogness
2020-03-03  9:47           ` Petr Mladek
2020-03-03 15:42             ` John Ogness
2020-03-04 10:09               ` Petr Mladek
2020-03-04  9:40           ` Petr Mladek
2020-01-28 16:19 ` [PATCH 2/2] printk: use the lockless ringbuffer John Ogness
2020-02-13  9:07   ` Sergey Senozhatsky
2020-02-13  9:42     ` John Ogness
2020-02-13 11:59       ` Sergey Senozhatsky
2020-02-13 22:36         ` John Ogness
2020-02-14  1:41           ` Sergey Senozhatsky
2020-02-14  2:09             ` Sergey Senozhatsky
2020-02-14  9:48             ` John Ogness
2020-02-14 13:29   ` lijiang
2020-02-14 13:50     ` John Ogness
2020-02-15  4:15       ` lijiang
2020-02-17 15:40       ` crashdump: " Petr Mladek
2020-02-17 16:14         ` John Ogness [this message]
2020-02-17 14:41   ` misc details: " Petr Mladek
2020-02-25 20:11     ` John Ogness
2020-02-26  9:54       ` Petr Mladek
2020-02-05  4:25 ` [PATCH 0/2] printk: replace ringbuffer lijiang
2020-02-05  4:42   ` Sergey Senozhatsky
2020-02-05  4:48   ` Sergey Senozhatsky
2020-02-05  5:02     ` Sergey Senozhatsky
2020-02-05  5:38       ` lijiang
2020-02-05  6:36         ` Sergey Senozhatsky
2020-02-05  9:00           ` John Ogness
2020-02-05  9:28             ` Sergey Senozhatsky
2020-02-05 10:19             ` lijiang
2020-02-05 16:12               ` John Ogness
2020-02-06  9:12                 ` lijiang
2020-02-13 13:07                 ` Petr Mladek
2020-02-14  1:07                   ` Sergey Senozhatsky
2020-02-05 11:07             ` Sergey Senozhatsky
2020-02-05 15:48               ` John Ogness
2020-02-05 19:29                 ` Joe Perches
2020-02-06  6:31                 ` Sergey Senozhatsky
2020-02-06  7:30                 ` lijiang
2020-02-07  1:40                 ` Steven Rostedt
2020-02-07  7:43                   ` John Ogness
2020-02-14 15:56                 ` Petr Mladek
2020-02-17 11:13                   ` John Ogness
2020-02-17 14:50                     ` Petr Mladek
2020-02-25 19:27                       ` John Ogness
2020-02-05  9:36           ` lijiang
2020-02-06  9:21 ` lijiang

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