From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Petr Mladek <pmladek@suse.com>,
Steven Rostedt <rostedt@goodmis.org>, Jan Kara <jack@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
Jiri Slaby <jslaby@suse.com>, Andreas Mohr <andi@lisas.de>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
linux-kernel@vger.kernel.org
Subject: Re: printk: what is going on with additional newlines?
Date: Mon, 28 Aug 2017 21:21:09 +0900 [thread overview]
Message-ID: <20170828122109.GA532@jagdpanzerIV.localdomain> (raw)
In-Reply-To: <20170828102830.GA403@jagdpanzerIV.localdomain>
On (08/28/17 19:28), Sergey Senozhatsky wrote:
> On (08/28/17 11:05), Pavel Machek wrote:
> > Hi!
> >
> > In 4.13-rc, printk("foo"); printk("bar"); seems to produce
> > foo\nbar. That's... quite surprising/unwelcome. What is going on
> > there? Are timestamps responsible?
>
> well, one thing we know for sure it is not related to this patch set ;)
>
>
> does any of the below patches fix the problem for you?
>
> basically it sets up the rule -- if we don't have LOG_NEWLINE lflags
> then we enforce LOG_CONT.
[..]
> @@ -1670,7 +1670,9 @@ static size_t log_output(int facility, int level, enum log_flags lflags, const c
> * write from the same process, try to add it to the buffer.
> */
> if (cont.len) {
> if (cont.owner == current && (lflags & LOG_CONT)) {
on the other hand... I don't think I like that check at all.
so I *probably* want to change it to -- !LOG_NEWLINE messages of the
same loglevel AND from the same task are getting concatenated.
a message with LOG_NEWLINE flushes the cont buffer.
for example:
printk("foo"); printk("foo"); printk("bar\n");
printk("buz"); printk("buz"); printk("buz"); pr_info("INFO msg\n");
printk("buz"); printk("buz"); printk("buz"); pr_err("ERR msg\n");
printk(KERN_CONT"foo"); printk(KERN_CONT"foo"); printk(KERN_CONT"bar\n");
printk(KERN_CONT"foo"); printk(KERN_CONT"foo"); printk(KERN_ERR"bar\n");
printk(KERN_CONT"foo"); printk(KERN_ERR"foo err"); printk(KERN_ERR"bar err\n");
for instance,
printk(KERN_ERR"foo err"); printk(KERN_ERR"bar err\n");
should produce "foo errbar err\n". from the same task and of
the same loglevel, no new line. must be cont messages with a missing
KERN_CONT. right?
so, for the examples I posted above, I think, the output must be
foofoobar
buzbuzbuz
INFO msg
buzbuzbuz
ERR msg
foofoobar
foofoo
bar
foo
foo errbar err
how about something like this?
---
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index fc47863f629c..675febf84dc8 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1670,10 +1670,9 @@ static size_t log_output(int facility, int level, enum log_flags lflags, const c
* write from the same process, try to add it to the buffer.
*/
if (cont.len) {
- if (cont.owner == current && (lflags & LOG_CONT)) {
+ if (cont.owner == current && cont.level == level)
if (cont_add(facility, level, lflags, text, text_len))
return text_len;
- }
/* Otherwise, make sure it's flushed */
cont_flush();
}
next prev parent reply other threads:[~2017-08-28 12:20 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-15 2:56 [RFC][PATCHv5 00/13] printk: introduce printing kernel thread Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 01/13] printk: move printk_pending out of per-cpu Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 02/13] printk: introduce printing kernel thread Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 03/13] printk: add sync printk_emergency API Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 04/13] printk: add enforce_emergency parameter Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 05/13] printk: enable printk offloading Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 06/13] printk: register PM notifier Sergey Senozhatsky
2017-08-15 11:51 ` Rafael J. Wysocki
2017-08-16 7:31 ` Sergey Senozhatsky
2017-08-16 12:58 ` Rafael J. Wysocki
2017-08-17 5:55 ` Sergey Senozhatsky
2017-08-17 15:43 ` Rafael J. Wysocki
2017-08-17 23:19 ` Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 07/13] printk: register syscore notifier Sergey Senozhatsky
2017-08-15 11:56 ` Rafael J. Wysocki
2017-08-16 6:55 ` Sergey Senozhatsky
2017-08-16 12:59 ` Rafael J. Wysocki
2017-08-15 2:56 ` [RFC][PATCHv5 08/13] printk: set watchdog_thresh as maximum value for atomic_print_limit Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 09/13] printk: add auto-emergency enforcement mechanism Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 10/13] printk: force printk_kthread to offload printing Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 11/13] printk: always offload printing from user-space processes Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 12/13] printk: do not cond_resched() when we can offload Sergey Senozhatsky
2017-08-15 2:56 ` [RFC][PATCHv5 13/13] printk: move offloading logic to per-cpu Sergey Senozhatsky
2017-08-23 8:33 ` [RFC][PATCHv5 00/13] printk: introduce printing kernel thread Sergey Senozhatsky
2017-08-28 9:05 ` printk: what is going on with additional newlines? Pavel Machek
2017-08-28 10:28 ` Sergey Senozhatsky
2017-08-28 12:21 ` Sergey Senozhatsky [this message]
2017-08-28 12:38 ` Sergey Senozhatsky
2017-08-28 12:46 ` Pavel Machek
2017-08-29 13:40 ` Sergey Senozhatsky
2017-08-29 16:37 ` Joe Perches
2017-08-29 17:00 ` Linus Torvalds
2017-08-29 17:12 ` Linus Torvalds
2017-08-29 20:41 ` Tetsuo Handa
2017-08-29 20:51 ` Linus Torvalds
2017-09-02 6:12 ` Tetsuo Handa
2017-09-02 17:06 ` Linus Torvalds
2017-08-29 23:50 ` Steven Rostedt
2017-08-29 23:59 ` Linus Torvalds
2017-08-30 1:03 ` Sergey Senozhatsky
2017-08-30 1:10 ` Steven Rostedt
2017-08-30 1:51 ` Sergey Senozhatsky
2017-08-30 1:52 ` Joe Perches
2017-08-30 2:25 ` Sergey Senozhatsky
2017-08-30 2:31 ` Joe Perches
2017-08-30 2:47 ` Sergey Senozhatsky
2017-08-30 2:58 ` Joe Perches
2017-08-30 5:37 ` Sergey Senozhatsky
2017-09-08 10:18 ` Pavel Machek
2017-09-05 9:44 ` Petr Mladek
2017-09-05 9:59 ` Sergey Senozhatsky
2017-09-05 12:21 ` Petr Mladek
2017-09-05 12:35 ` Tetsuo Handa
2017-09-05 14:18 ` Sergey Senozhatsky
2017-09-05 13:42 ` Sergey Senozhatsky
2017-09-06 7:55 ` Petr Mladek
2017-09-17 6:26 ` Sergey Senozhatsky
2017-09-17 9:27 ` Sergey Senozhatsky
2017-09-17 15:35 ` Linus Torvalds
2017-09-18 0:46 ` Sergey Senozhatsky
2017-09-18 2:22 ` Joe Perches
2017-09-18 2:41 ` Sergey Senozhatsky
2017-09-18 2:45 ` Joe Perches
2017-09-18 2:55 ` Sergey Senozhatsky
2017-09-18 3:07 ` Joe Perches
2017-09-18 4:42 ` Sergey Senozhatsky
2017-09-01 13:19 ` Sergey Senozhatsky
2017-09-01 17:32 ` Joe Perches
2017-09-01 20:21 ` Linus Torvalds
2017-09-04 5:22 ` Sergey Senozhatsky
2017-09-04 5:41 ` Joe Perches
2017-09-05 14:54 ` Steven Rostedt
2017-09-06 2:14 ` Sergey Senozhatsky
2017-09-06 2:36 ` Linus Torvalds
2017-09-04 4:30 ` Sergey Senozhatsky
2017-09-04 5:24 ` Sergey Senozhatsky
2017-08-29 17:33 ` Sergey Senozhatsky
2017-08-29 17:52 ` Linus Torvalds
2017-08-29 18:09 ` Joe Perches
2017-08-30 1:07 ` Sergey Senozhatsky
2017-08-30 0:58 ` Sergey Senozhatsky
2017-08-29 16:48 ` Linus Torvalds
2017-08-29 17:10 ` Joe Perches
2017-08-29 17:20 ` Linus Torvalds
2017-08-29 17:33 ` Joe Perches
2017-08-29 17:36 ` Linus Torvalds
2017-08-29 17:48 ` Joe Perches
2017-08-29 20:24 ` Pavel Machek
2017-09-01 1:40 ` Sergey Senozhatsky
2017-09-01 2:04 ` Joe Perches
2017-09-01 6:59 ` Pavel Machek
2017-09-01 7:23 ` Joe Perches
2017-09-01 7:29 ` Pavel Machek
2017-09-01 11:13 ` Steven Rostedt
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