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Subject: Re: [PATCH] ext4: disable mount with both dioread_nolock and
 nodelalloc
To:     "Theodore Y. Ts'o" <tytso@mit.edu>
Cc:     linux-ext4@vger.kernel.org
References: <20190731130600.7867-1-xiaoguang.wang@linux.alibaba.com>
 <20190907160004.GB23683@mit.edu>
From:   Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Message-ID: <fb03f569-6b38-9a85-3828-f814a5aec313@linux.alibaba.com>
Date:   Mon, 9 Sep 2019 11:40:34 +0800
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hi,

> 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.
Yes, agree, then should we have some places to record this issue? In case
somebody looks into it again.

Regards,
Xiaoguang Wang

> 
> 	    	     	  	      	 - Ted
>