From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Jan Kara <jack@suse.com>, Tejun Heo <tj@kernel.org>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
linux-kernel@vger.kernel.org,
Byungchul Park <byungchul.park@lge.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Jan Kara <jack@suse.cz>
Subject: Re: [RFC][PATCH v9 1/2] printk: Make printk() completely async
Date: Sat, 2 Apr 2016 01:39:17 +0900 [thread overview]
Message-ID: <20160401163917.GC1212@swordfish> (raw)
In-Reply-To: <20160401150032.GE1023@pathway.suse.cz>
On (04/01/16 17:00), Petr Mladek wrote:
> You need to move this assigment right above the console_lock()/console_unlock()
> calls. Otherwise, there is a race:
>
> CPU0: CPU1
>
> printk_kthread_func()
>
> console_unlock()
>
> printk()
>
> printk_kthread_need_flush_console = true;
> wake_up_process(printk_kthread);
>
> printk_kthread_need_flush_console = false;
>
> set_current_state(TASK_INTERRUPTIBLE);
> if (!printk_kthread_need_flush_console)
> schedule();
thanks. yeah, this can add latency to some messages.
-ss
next prev parent reply other threads:[~2016-04-01 16:41 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-01 14:10 [RFC][PATCH v9 0/2] printk: Make printk() completely async Sergey Senozhatsky
2016-04-01 14:10 ` [RFC][PATCH v9 1/2] " Sergey Senozhatsky
2016-04-01 15:00 ` Petr Mladek
2016-04-01 16:39 ` Sergey Senozhatsky [this message]
[not found] ` <201604012226.FSdLC1Bk%fengguang.wu@intel.com>
2016-04-01 16:33 ` Sergey Senozhatsky
2016-04-01 14:10 ` [RFC][PATCH v9 2/2] printk: Make wake_up_klogd_work_func() async Sergey Senozhatsky
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