Re: [PATCH v4 3/3] mm: fs: Invalidate BH LRU during page migration

[Minchan Kim]

On Sat, Mar 20, 2021 at 09:32:49AM -0700, Andrew Morton wrote:
> On Fri, 19 Mar 2021 10:51:27 -0700 Minchan Kim <minchan@xxxxxxxxxx> wrote:
> 
> > Pages containing buffer_heads that are in one of the per-CPU
> > buffer_head LRU caches will be pinned and thus cannot be migrated.
> > This can prevent CMA allocations from succeeding, which are often used
> > on platforms with co-processors (such as a DSP) that can only use
> > physically contiguous memory. It can also prevent memory
> > hot-unplugging from succeeding, which involves migrating at least
> > MIN_MEMORY_BLOCK_SIZE bytes of memory, which ranges from 8 MiB to 1
> > GiB based on the architecture in use.
> > 
> > Correspondingly, invalidate the BH LRU caches before a migration
> > starts and stop any buffer_head from being cached in the LRU caches,
> > until migration has finished.
> > 
> > Tested-by: Oliver Sang <oliver.sang@xxxxxxxxx>
> > Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> > Signed-off-by: Chris Goldsworthy <cgoldswo@xxxxxxxxxxxxxx>
> > Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
> 
> The signoff chain ordering might mean that Chris was the primary author, but
> there is no From:him.  Please clarify?

He tried first version but was diffrent implementation since I
changed a lot. That's why I added his SoB even though current
implementaion is much different. So, maybe I am primary author?