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Message-ID: <1504060296.2786.8.camel@perches.com>
Subject: Re: printk: what is going on with additional newlines?
From: Joe Perches <joe@perches.com>
To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
        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>
Date: Tue, 29 Aug 2017 19:31:36 -0700
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On Wed, 2017-08-30 at 11:25 +0900, Sergey Senozhatsky wrote:
> On (08/29/17 18:52), Joe Perches wrote:
> [..]
> > > 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.
> 
> the idea is not to do printk() on that seq buffer at all, but to
> log_store(), atomically, seq buffer messages
> 
> 	spin_lock(&logbuf_lock)
> 	while (offset < seq_buffer->len) {
> 		...
> 		log_store(seq->buffer + offset);
> 		...
> 	}
> 	spin_unlock(&logbuf_unlock)

Why?

What's wrong with a simple printk?
It'd still do a log_store.