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Sender: Minchan Kim <minchan.kim@gmail.com>
Date:   Sat, 20 Mar 2021 10:20:09 -0700
From:   Minchan Kim <minchan@kernel.org>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-mm <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>,
        joaodias@google.com, surenb@google.com, cgoldswo@codeaurora.org,
        willy@infradead.org, mhocko@suse.com, david@redhat.com,
        vbabka@suse.cz, linux-fsdevel@vger.kernel.org,
        oliver.sang@intel.com
Subject: Re: [PATCH v4 3/3] mm: fs: Invalidate BH LRU during page migration
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References: <20210319175127.886124-1-minchan@kernel.org>
 <20210319175127.886124-3-minchan@kernel.org>
 <20210320093249.2df740cd139449312211c452@linux-foundation.org>
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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@kernel.org> 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@intel.com>
> > Reported-by: kernel test robot <oliver.sang@intel.com>
> > Signed-off-by: Chris Goldsworthy <cgoldswo@codeaurora.org>
> > Signed-off-by: Minchan Kim <minchan@kernel.org>
> 
> 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?