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Date: Tue, 22 Sep 2015 16:26:04 -0400
From: Tejun Heo <tj@kernel.org>
To: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, Oleg Nesterov <oleg@redhat.com>,
        Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Josh Triplett <josh@joshtriplett.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Jiri Kosina <jkosina@suse.cz>, Borislav Petkov <bp@suse.de>,
        Michal Hocko <mhocko@suse.cz>, linux-mm@kvack.org,
        Vlastimil Babka <vbabka@suse.cz>, live-patching@vger.kernel.org,
        linux-api@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC v2 09/18] mm/huge_page: Convert khugepaged() into kthread
 worker API
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References: <1442840639-6963-1-git-send-email-pmladek@suse.com>
 <1442840639-6963-10-git-send-email-pmladek@suse.com>
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Hello,

On Mon, Sep 21, 2015 at 03:03:50PM +0200, Petr Mladek wrote:
> +static int khugepaged_has_work(void)
> +{
> +	return !list_empty(&khugepaged_scan.mm_head) &&
> +		khugepaged_enabled();
> +}

Hmmm... no biggie but this is a bit bothering.

> @@ -425,7 +447,10 @@ static ssize_t scan_sleep_millisecs_store(struct kobject *kobj,
>  		return -EINVAL;
>  
>  	khugepaged_scan_sleep_millisecs = msecs;
> -	wake_up_interruptible(&khugepaged_wait);
> +	if (khugepaged_has_work())
> +		mod_delayed_kthread_work(khugepaged_worker,
> +					 &khugepaged_do_scan_work,
> +					 0);

What's wrong with just doing the following?

	if (khugepaged_enabled())
		mod_delayed_kthread_work(...);

Thanks.

-- 
tejun