From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
Steven Rostedt <rostedt@goodmis.org>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.cz>,
linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] printk: Correctly handle preemption in console_unlock()
Date: Mon, 16 Jan 2017 13:43:28 +0000 [thread overview]
Message-ID: <20170116134328.GB23242@tigerII.localdomain> (raw)
In-Reply-To: <20170116132633.GA23242@tigerII.localdomain>
On (01/16/17 22:26), Sergey Senozhatsky wrote:
> On (01/16/17 13:48), Petr Mladek wrote:
> [..]
> > The async printk code looks like this:
> >
> > vprintk_emit(...)
> > {
> >
> >
> > if (can_printk_async()) {
> > /* Offload printing to a schedulable context. */
> > printk_kthread_need_flush_console = true;
> > wake_up_process(printk_kthread);
> > } else {
> > /*
> > * Try to acquire and then immediately release the
> > * console semaphore. The release will print out
> > * buffers and wake up /dev/kmsg and syslog() users.
> > */
> > if (console_trylock())
> > console_unlock();
> > }
> >
> > So, there is still the console_trylock() for the sync mode. Or do I
> > see an outdated variant?
>
> no, it doesn't.
I meant that none of this is happening in vprintk_emit(). there is no
console_sem in vprintk_emit() at all. eveything is done in deferred printk.
-ss
next prev parent reply other threads:[~2017-01-16 13:43 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-13 13:15 [PATCH] printk: Correctly handle preemption in console_unlock() Petr Mladek
2017-01-13 16:05 ` Steven Rostedt
2017-01-16 11:00 ` Petr Mladek
2017-01-18 5:45 ` Sergey Senozhatsky
2017-01-18 7:21 ` Sergey Senozhatsky
2017-01-25 12:34 ` Petr Mladek
2017-01-14 6:28 ` Sergey Senozhatsky
2017-01-16 11:38 ` Petr Mladek
2017-01-16 11:58 ` Sergey Senozhatsky
2017-01-16 12:48 ` Petr Mladek
2017-01-16 13:26 ` Sergey Senozhatsky
2017-01-16 13:43 ` Sergey Senozhatsky [this message]
2017-01-16 14:14 ` Petr Mladek
2017-01-16 15:19 ` Sergey Senozhatsky
2017-01-16 15:43 ` Sergey Senozhatsky
2017-01-16 16:35 ` Petr Mladek
2017-01-16 13:41 ` Tetsuo Handa
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