From: Joe Perches <joe@perches.com>
To: Steven Rostedt <rostedt@goodmis.org>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Pavel Machek <pavel@ucw.cz>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Petr Mladek <pmladek@suse.com>, 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 Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: printk: what is going on with additional newlines?
Date: Tue, 29 Aug 2017 18:52:39 -0700 [thread overview]
Message-ID: <1504057959.2786.4.camel@perches.com> (raw)
In-Reply-To: <20170829211046.74644c8a@gandalf.local.home>
On Tue, 2017-08-29 at 21:10 -0400, Steven Rostedt wrote:
> On Wed, 30 Aug 2017 10:03:48 +0900
> Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> wrote:
>
> > Hello,
> >
> > On (08/29/17 19:50), Steven Rostedt wrote:
> > [..]
> > > > A private buffer has none of those issues.
> > >
> > > What about using the seq_buf*() then?
> > >
> > > struct seq_buf s;
> > >
> > > buf = kmalloc(mysize);
> > > seq_buf_init(&s, buf, mysize);
> > >
> > > seq_printf(&s,"blah blah %d", bah_blah);
> > > [...]
> > > seq_printf(&s, "my last print\n");
> > >
> > > printk("%.*s", s.len, s.buffer);
> > >
> > > kfree(buf);
> >
> > could do. for a single continuation line printk("%.*s", s.len, s.buffer)
> > this will work perfectly fine. for a more general case - backtraces, dumps,
> > etc. - this requires some tweaks.
>
> We could simply add a seq_buf_printk() that is implemented in the printk
> proper, to parse the seq_buf buffer properly, and add the timestamps and
> such.
No need. printk would already add timestamps.
One addition might be to add a bit to initialize
the buffer so that printk("%s", s->buffer) is simpler.
---
diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h
index fb7eb9ccb1cd..fb6c9de0ee33 100644
--- a/include/linux/seq_buf.h
+++ b/include/linux/seq_buf.h
@@ -26,6 +26,7 @@ static inline void seq_buf_clear(struct seq_buf *s)
{
s->len = 0;
s->readpos = 0;
+ *s->buffer = 0;
}
static inline void
next prev parent reply other threads:[~2017-08-30 1:52 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
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 [this message]
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
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=1504057959.2786.4.camel@perches.com \
--to=joe@perches.com \
--cc=akpm@linux-foundation.org \
--cc=andi@lisas.de \
--cc=jack@suse.cz \
--cc=jslaby@suse.com \
--cc=linux-kernel@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=penguin-kernel@i-love.sakura.ne.jp \
--cc=pmladek@suse.com \
--cc=rostedt@goodmis.org \
--cc=sergey.senozhatsky.work@gmail.com \
--cc=sergey.senozhatsky@gmail.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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).