Re: [patch] mm, thp: always direct reclaim for MADV_HUGEPAGE even when deferred

[Kirill A. Shutemov]

On Wed, Dec 21, 2016 at 04:21:54PM -0800, David Rientjes wrote:
> Currently, when defrag is set to "madvise", thp allocations will direct
> reclaim.  However, when defrag is set to "defer", all thp allocations do
> not attempt reclaim regardless of MADV_HUGEPAGE.
> 
> This patch always directly reclaims for MADV_HUGEPAGE regions when defrag
> is not set to "never."  The idea is that MADV_HUGEPAGE regions really
> want to be backed by hugepages and are willing to endure the latency at
> fault as it was the default behavior prior to commit 444eb2a449ef ("mm:
> thp: set THP defrag by default to madvise and add a stall-free defrag
> option").
> 
> In this form, "defer" is a stronger, more heavyweight version of
> "madvise".
> 
> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>

Makes senses to me.

Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

-- 
 Kirill A. Shutemov