Re: [PATCH v6 02/15] btrfs: remove the GFP_HIGHMEM flag for compression code

On Mon, Jul 05, 2021 at 10:00:57AM +0800, Qu Wenruo wrote:

This allows later decompress functions to get rid of kmap()/kunmap()
pairs.

And since all other filesystems are getting rid of HIGHMEM, it should
not be a problem for btrfs.

Although we removed the HIGHMEM allocation, we still keep the
kmap()/kunmap() pairs.
They will be removed when involved functions are refactored later.

I've sent the highmem cleanup and will drop this patch, there should be
minimal conflicts in the followup changes.