LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Petr Mladek <pmladek@suse.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Alexander Potapenko <glider@google.com>,
	Dmitriy Vyukov <dvyukov@google.com>,
	kbuild test robot <fengguang.wu@intel.com>,
	syzkaller <syzkaller@googlegroups.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] printk: inject caller information into the body of message
Date: Sat, 29 Sep 2018 20:39:34 +0900
Message-ID: <469bcffe-9e5b-d69f-da63-2a491c0e370b@i-love.sakura.ne.jp> (raw)
In-Reply-To: <20180929111317.GB1392@tigerII.localdomain>

On 2018/09/29 20:13, Sergey Senozhatsky wrote:
> On (09/28/18 20:21), Tetsuo Handa wrote:
>> On 2018/09/28 17:56, Sergey Senozhatsky wrote:
>>> The good thing about cont buffer is that we flush it on panic. E.g.
>>> core/arch early boot stage can do:
>>>
>>> 	pr_cont("going to call early_init_foo()...");
>>> 	early_init_foo();
>>> 	pr_cont("OK\n");
>>>
>>
>> Is printing
>>
>>   going to call early_init_foo()...OK
>>
>> in one line so critically important?
> 
> Could be. If this is the last thing you are about to see on your
> serial console. panic_on_flush() is not guaranteed to succeed.

Doing

  printk("going to call early_init_foo()...\n");
  early_init_foo();
  printk("OK\n");

and getting

  T0: going to call early_init_foo()...

as the last line we see on our serial console will not be so bad.

Implicitly flushing incomplete lines might disturb automated processing.
But there is after all other factors which can disturb automated
processing (e.g. "** %u printk messages dropped **\n" in printk(),
UDP packet being lost when transmitting via netconsole). After all,
we cannot allow perfect automated processing. The last help is
human's eyes and brain.

Then, prefixing caller information helps even if incomplete line
is implicitly flushed by line buffered printk() API...

  reply index

Thread overview: 94+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <201804232233.CIC65675.OJSOMFQOFFHVtL@I-love.SAKURA.ne.jp>
     [not found] ` <CACT4Y+boyw_Qy=y-iTnsKZrtTgF0Hk3nHN_xtqUdX4etgiYDQw@mail.gmail.com>
2018-04-24  1:33   ` printk feature for syzbot? Sergey Senozhatsky
2018-04-24 14:40     ` Steven Rostedt
2018-04-26 10:06     ` Petr Mladek
2018-05-10  4:22       ` Sergey Senozhatsky
2018-05-10 11:30         ` Petr Mladek
2018-05-10 12:11           ` Sergey Senozhatsky
2018-05-10 14:22             ` Steven Rostedt
2018-05-10 14:50         ` Tetsuo Handa
2018-05-11  1:45           ` Sergey Senozhatsky
     [not found]             ` <201805110238.w4B2cIGH079602@www262.sakura.ne.jp>
2018-05-11  6:21               ` Sergey Senozhatsky
2018-05-11  9:17                 ` Dmitry Vyukov
2018-05-11  9:50                   ` Sergey Senozhatsky
2018-05-11 11:58                     ` [PATCH] printk: inject caller information into the body of message Tetsuo Handa
2018-05-17 11:21                       ` Sergey Senozhatsky
2018-05-17 11:52                         ` Sergey Senozhatsky
2018-05-18 12:15                         ` Petr Mladek
2018-05-18 12:25                           ` Dmitry Vyukov
2018-05-18 12:54                             ` Petr Mladek
2018-05-18 13:08                               ` Dmitry Vyukov
2018-05-24  2:21                                 ` Sergey Senozhatsky
2018-05-23 10:19                           ` Tetsuo Handa
2018-05-24  2:14                           ` Sergey Senozhatsky
2018-05-26  6:36                             ` Dmitry Vyukov
2018-06-20  5:44                               ` Dmitry Vyukov
2018-06-20  8:31                                 ` Sergey Senozhatsky
2018-06-20  8:45                                   ` Dmitry Vyukov
2018-06-20  9:06                                     ` Sergey Senozhatsky
2018-06-20  9:18                                       ` Sergey Senozhatsky
2018-06-20  9:31                                         ` Dmitry Vyukov
2018-06-20 11:07                                           ` Sergey Senozhatsky
2018-06-20 11:32                                             ` Dmitry Vyukov
2018-06-20 13:06                                               ` Sergey Senozhatsky
2018-06-22 13:06                                                 ` Tetsuo Handa
2018-06-25  1:41                                                   ` Sergey Senozhatsky
2018-06-25  9:36                                                     ` Dmitry Vyukov
2018-06-27 10:29                                                       ` Tetsuo Handa
2018-09-10 11:20                                                 ` Alexander Potapenko
2018-09-12  6:53                                                   ` Sergey Senozhatsky
2018-09-12 16:05                                                     ` Steven Rostedt
2018-09-13  7:12                                                       ` Sergey Senozhatsky
2018-09-13 12:26                                                         ` Petr Mladek
2018-09-13 14:28                                                           ` Sergey Senozhatsky
2018-09-14  1:22                                                             ` Steven Rostedt
2018-09-14  2:15                                                               ` Sergey Senozhatsky
2018-09-14  6:57                                                             ` Sergey Senozhatsky
2018-09-14 10:37                                                               ` Tetsuo Handa
2018-09-14 11:50                                                                 ` Sergey Senozhatsky
2018-09-14 12:03                                                                   ` Tetsuo Handa
2018-09-14 12:22                                                                     ` Sergey Senozhatsky
2018-09-19 11:02                                                                       ` Tetsuo Handa
2018-09-24  8:11                                                                         ` Tetsuo Handa
2018-09-27 16:10                                                                           ` Tetsuo Handa
2018-09-28  9:02                                                                             ` Sergey Senozhatsky
2018-09-28  9:09                                                                           ` Sergey Senozhatsky
2018-09-28 11:01                                                                             ` Tetsuo Handa
2018-09-29 10:51                                                                               ` Sergey Senozhatsky
2018-09-29 11:15                                                                                 ` Tetsuo Handa
2018-10-01  2:37                                                                                   ` Sergey Senozhatsky
2018-10-01  2:58                                                                                     ` Sergey Senozhatsky
2018-10-01 11:21                                                                                     ` Tetsuo Handa
2018-10-02  6:38                                                                                       ` Sergey Senozhatsky
2018-10-08 10:31                                                                                         ` Tetsuo Handa
2018-10-08 16:03                                                                                           ` Petr Mladek
2018-10-08 20:48                                                                                             ` Tetsuo Handa
2018-10-09 14:52                                                                                               ` Petr Mladek
2018-10-09 21:19                                                                                                 ` Tetsuo Handa
2018-10-10 10:14                                                                                                   ` Tetsuo Handa
2018-10-11 10:20                                                                                                     ` Tetsuo Handa
2018-10-11 13:47                                                                                                       ` Steven Rostedt
2018-10-08 15:43                                                                                         ` Petr Mladek
2018-09-28  8:56                                                                         ` Sergey Senozhatsky
2018-09-28 11:21                                                                           ` Tetsuo Handa
2018-09-29 11:13                                                                             ` Sergey Senozhatsky
2018-09-29 11:39                                                                               ` Tetsuo Handa [this message]
2018-10-01  5:52                                                                               ` Sergey Senozhatsky
2018-10-01  8:37                                                                                 ` Sergey Senozhatsky
2018-10-01 18:06                                                                               ` Steven Rostedt
2018-09-14  1:12                                                         ` Steven Rostedt
2018-09-14  1:55                                                           ` Sergey Senozhatsky
2018-06-21  8:29                                               ` Sergey Senozhatsky
2018-06-20  9:30                                       ` Dmitry Vyukov
2018-06-20 11:19                                         ` Sergey Senozhatsky
2018-06-20 11:25                                           ` Dmitry Vyukov
2018-06-20 11:37                                         ` Fengguang Wu
2018-06-20 12:31                                           ` Dmitry Vyukov
2018-06-20 12:41                                             ` Fengguang Wu
2018-06-20 12:45                                               ` Dmitry Vyukov
2018-06-20 12:48                                                 ` Fengguang Wu
2018-05-11 13:37                     ` printk feature for syzbot? Steven Rostedt
2018-05-15  5:20                       ` Sergey Senozhatsky
2018-05-15 14:39                         ` Steven Rostedt
2018-05-11 11:02                 ` [PATCH] printk: fix possible reuse of va_list variable Tetsuo Handa
2018-05-11 11:27                   ` Sergey Senozhatsky
2018-05-17 11:57                   ` Petr Mladek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=469bcffe-9e5b-d69f-da63-2a491c0e370b@i-love.sakura.ne.jp \
    --to=penguin-kernel@i-love.sakura.ne.jp \
    --cc=akpm@linux-foundation.org \
    --cc=dvyukov@google.com \
    --cc=fengguang.wu@intel.com \
    --cc=glider@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pmladek@suse.com \
    --cc=rostedt@goodmis.org \
    --cc=sergey.senozhatsky.work@gmail.com \
    --cc=sergey.senozhatsky@gmail.com \
    --cc=syzkaller@googlegroups.com \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git
	git clone --mirror https://lore.kernel.org/lkml/10 lkml/git/10.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git