From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: John Ogness <john.ogness@linutronix.de>
Cc: Petr Mladek <pmladek@suse.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
kexec@lists.infradead.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: POC: Alternative solution: Re: [PATCH 0/4] printk: reimplement LOG_CONT handling
Date: Thu, 13 Aug 2020 14:18:53 +0900 [thread overview]
Message-ID: <20200813051853.GA510@jagdpanzerIV.localdomain> (raw)
In-Reply-To: <87v9hn2y1p.fsf@jogness.linutronix.de>
On (20/08/13 02:30), John Ogness wrote:
> 2. I haven't yet figured out how to preserve calling context when a
> newline appears. For example:
>
> pr_info("text");
> pr_cont(" 1");
> pr_cont(" 2\n");
> pr_cont("3");
> pr_cont(" 4\n");
>
> For "3" the calling context (info, timestamp) is lost because with "2"
> the record is finalized. Perhaps the above is invalid usage of LOG_CONT?
This is not an unseen pattern, I'm afraid. And the problem here can
be more general:
pr_info("text");
pr_cont("1");
exception/IRQ/NMI
pr_alert("text\n");
pr_cont("2");
pr_cont("\n");
I guess the solution would be to store "last log_level" in task_struct
and get current (new) timestamp for broken cont line?
We have this problem now. E.g. early boot messages from one of my boxes:
6,173,41837,-;x86: Booting SMP configuration:
6,174,41838,-;.... node #0, CPUs: #1 #2 #3 #4
4,175,44993,-;MDS CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/...
4,176,44993,c; #5 #6 #7
"CPUs: #1 #2 #3 #4 #5 #6 #7" is supposed to be one cont line with
loglevel 6. But it gets interrupted and flushed so that "#5 #6 #7"
appears with the different loglevel.
-ss
next prev parent reply other threads:[~2020-08-13 5:18 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 23:48 [PATCH 0/4] printk: reimplement LOG_CONT handling John Ogness
2020-07-17 23:48 ` [PATCH 1/4] printk: ringbuffer: support dataless records John Ogness
2020-07-20 14:49 ` John Ogness
2020-07-17 23:48 ` [PATCH 2/4] printk: store instead of processing cont parts John Ogness
2020-07-19 14:35 ` Sergey Senozhatsky
2020-07-19 18:27 ` Linus Torvalds
2020-07-20 1:50 ` Sergey Senozhatsky
2020-07-20 18:30 ` Linus Torvalds
2020-07-21 3:53 ` Joe Perches
2020-07-21 14:42 ` Sergey Senozhatsky
2020-07-21 14:57 ` John Ogness
2020-07-29 2:03 ` Sergey Senozhatsky
2020-07-21 15:40 ` Linus Torvalds
2020-07-28 2:22 ` Sergey Senozhatsky
2020-07-17 23:48 ` [PATCH 3/4] printk: process cont records during reading John Ogness
2020-07-17 23:48 ` [PATCH 4/4] ipconfig: cleanup printk usage John Ogness
2020-07-18 0:00 ` [PATCH 0/4] printk: reimplement LOG_CONT handling Linus Torvalds
2020-07-18 14:42 ` John Ogness
2020-07-18 17:42 ` Linus Torvalds
2020-08-11 16:05 ` Petr Mladek
2020-08-12 16:39 ` POC: Alternative solution: " Petr Mladek
2020-08-13 0:24 ` John Ogness
2020-08-13 5:18 ` Sergey Senozhatsky [this message]
2020-08-13 7:44 ` John Ogness
2020-08-13 8:41 ` Petr Mladek
2020-08-13 10:29 ` John Ogness
2020-08-13 11:30 ` Petr Mladek
2020-08-14 3:34 ` Sergey Senozhatsky
2020-08-14 8:16 ` John Ogness
2020-08-14 9:12 ` Petr Mladek
2020-08-13 11:54 ` Sergey Senozhatsky
2020-08-14 9:04 ` Petr Mladek
2020-08-14 22:46 ` Linus Torvalds
2020-08-14 23:52 ` Joe Perches
2020-08-15 2:33 ` Linus Torvalds
2020-08-15 3:08 ` Joe Perches
2020-08-15 9:25 ` David Laight
2020-08-15 5:41 ` Sergey Senozhatsky
2020-08-13 7:51 ` Petr Mladek
2020-08-13 7:31 ` Petr Mladek
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