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Reply-To: "Hillf Danton" <hillf.zj@alibaba-inc.com>
From: "Hillf Danton" <hillf.zj@alibaba-inc.com>
To: <zhouxianrong@huawei.com>, <linux-mm@kvack.org>
Cc: <linux-kernel@vger.kernel.org>, <akpm@linux-foundation.org>,
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In-Reply-To: <1476774765-21130-1-git-send-email-zhouxianrong@huawei.com>
Subject: Re: [PATCH] bdi flusher should not be throttled here when it fall into buddy slow path
Date: Tue, 18 Oct 2016 17:34:41 +0800
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> @@ -1908,7 +1908,7 @@ void wb_workfn(struct work_struct *work)
>  	long pages_written;
> 
>  	set_worker_desc("flush-%s", dev_name(wb->bdi->dev));
> -	current->flags |= PF_SWAPWRITE;

If flags carries PF_LESS_THROTTLE before modified, then you 
have to restore it. 

> +	current->flags |= (PF_SWAPWRITE | PF_BDI_FLUSHER | PF_LESS_THROTTLE);
> 
>  	if (likely(!current_is_workqueue_rescuer() ||
>  		   !test_bit(WB_registered, &wb->state))) {
> @@ -1938,7 +1938,7 @@ void wb_workfn(struct work_struct *work)
>  	else if (wb_has_dirty_io(wb) && dirty_writeback_interval)
>  		wb_wakeup_delayed(wb);
> 
> -	current->flags &= ~PF_SWAPWRITE;
> +	current->flags &= ~(PF_SWAPWRITE | PF_BDI_FLUSHER | PF_LESS_THROTTLE);
>  }
> 
thanks
Hillf