Re: [RFC PATCH v4 9/9] printk: use a new ringbuffer implementation

[Peter Zijlstra]

On Thu, Aug 08, 2019 at 12:07:28PM -0700, Linus Torvalds wrote:

> End result: a DRAM buffer can work, but is not "reliable".
> Particularly if you turn power on and off, data retention of DRAM is
> iffy. But it's possible, at least in theory.
> 
> So I have a patch that implements a "stupid ring buffer" for thisa
> case, with absolutely zero data structures (because in the presense of
> DRAM corruption, all you can get is "hopefully only slightly garbled
> ASCII".

Note that you can hook this into printk as a fake early serial device;
just have the serial device write to the DRAM buffer.