Re: Re: [BUG] ramfs system panic when using dd to create files

[wuzhouhui <wuzhouhui14@xxxxxxxxxxxxxxxx>]

> -----Original Messages-----
&gt; From: "yong w" <yongw.pur@xxxxxxxxx>
&gt; Sent Time: 2021-07-14 08:24:23 (Wednesday)
&gt; To: linux-kernel@xxxxxxxxxxxxxxx, linux-mm@xxxxxxxxx, akpm@xxxxxxxxxxxxxxxxxxxx, nico@xxxxxxxxxxx, wang.yong12@xxxxxxxxxx
&gt; Cc: 
&gt; Subject: Re: [BUG] ramfs system panic when using dd to create files
&gt; 
&gt; Hello, is there any solution, or how to avoid this problem when using ramfs?

Limit max size of ramfs.

&gt; 
&gt; yong w <yongw.pur@xxxxxxxxx> 于2021年7月7日周三 下午5:58写道：
&gt; &gt;
&gt; &gt; When I  use dd to create files multiple times under the ramfs file
&gt; &gt; system，Panic appears, indicating that there is no process to kill.
&gt; &gt; I learn that ramfs will automatically grow space due to data writing,
&gt; &gt; causing all the system memory to run out,  but i think it shouldn't
&gt; &gt; cause the system to panic.

The comments already explains why kernel should panic on this situation:
            /*
             * If we got here due to an actual allocation at the
             * system level, we cannot survive this and will enter
             * an endless loop in the allocator. Bail out now.
             */
</yongw.pur@xxxxxxxxx></yongw.pur@xxxxxxxxx>