[dm-devel] [PATCH v2] dm-writecache: avoid kcopyd and use open-coded variant instead

[Mikulas Patocka]

On Thu, 10 Jun 2021, Christoph Hellwig wrote:

> On Wed, Jun 09, 2021 at 09:38:38AM -0400, Mikulas Patocka wrote:
> > Hi
> > 
> > This is the second version of the patch that avoids kcopyd. It sorts the 
> > requests according to sector number when writing to the slow device. But 
> > still, kcopyd is faster in my tests.
> 
> So kcopyd is faster but you replace it by an open coded version?
> Why?

I thought that the open-coded version would perform better. This is just a 
test patch, I do not intend to push upstream. I tested it on IDE disk and 
SATA300 ssd. I am interested to see how it will perform on NVME ssd.

Mikulas