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Date:   Sat, 7 Sep 2019 12:00:04 -0400
From:   "Theodore Y. Ts'o" <tytso@mit.edu>
To:     Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Cc:     linux-ext4@vger.kernel.org
Subject: Re: [PATCH] ext4: disable mount with both dioread_nolock and
 nodelalloc
Message-ID: <20190907160004.GB23683@mit.edu>
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On Wed, Jul 31, 2019 at 09:06:00PM +0800, Xiaoguang Wang wrote:
> Mount with both dioread_nolock and nodelalloc will result in huge
> performance drop, which indeed is an known issue, so before we fix
> this issue, currently we disable this behaviour. Below test reproducer
> can reveal this performance drop.

Is it really worth it to disable this combination?  Nothing goes
*wrong* per se; it's just slower than we would like.

	    	     	  	      	 - Ted