Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 7 Oct 2019 14:01:34 +0200
From:   Petr Mladek <pmladek@suse.com>
To:     Tony Asleson <tasleson@redhat.com>
Cc:     John Ogness <john.ogness@linutronix.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Andrea Parri <parri.andrea@gmail.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Brendan Higgins <brendanhiggins@google.com>,
        Paul Turner <pjt@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Theodore Ts'o <tytso@mit.edu>,
        David Lehman <dlehman@redhat.com>,
        Jeff Moyer <jmoyer@redhat.com>,
        Prarit Bhargava <prarit@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: Re: printk meeting at LPC
Message-ID: <20191007120134.ciywr3wale4gxa6v@pathway.suse.cz>
References: <20190807222634.1723-1-john.ogness@linutronix.de>
 <20190904123531.GA2369@hirez.programming.kicks-ass.net>
 <20190905130513.4fru6yvjx73pjx7p@pathway.suse.cz>
 <20190905143118.GP2349@hirez.programming.kicks-ass.net>
 <alpine.DEB.2.21.1909051736410.1902@nanos.tec.linutronix.de>
 <20190905121101.60c78422@oasis.local.home>
 <alpine.DEB.2.21.1909091507540.1791@nanos.tec.linutronix.de>
 <87k1acz5rx.fsf@linutronix.de>
 <30f29fe6-8445-0016-8cdc-3ef99d43fbf5@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <30f29fe6-8445-0016-8cdc-3ef99d43fbf5@redhat.com>
User-Agent: NeoMutt/20170912 (1.9.0)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri 2019-10-04 09:48:24, Tony Asleson wrote:
> On 9/13/19 8:26 AM, John Ogness wrote:
> > 9. Support for printk dictionaries will be discontinued. I will look
> > into who is using this and why. If printk dictionaries are important for
> > you, speak up now!
> 
> I think this functionality is important.
> 
> I've been experimenting with a change which adds dictionary data to
> storage related printk messages so that a persistent durable id is
> associated with them for filtering, eg.
> 
> $ journalctl -r _KERNEL_DURABLE_NAME=naa.0000000000bc614e
> 
> This has the advantage that when the device attachment changes across
> reboots or detach/reattach cycles you can easily find its messages
> throughout it's recorded history.

Thanks for the pointers. I think that we will need to keep the
dictionaries then.

Just for explanation. We were not aware of this functionality when
it was discussed. The expectation was that this feature has never
been used in userspace. We were too optimistic ;-)

Best Regards,
Petr