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    Revert "Revert "mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask"" · 92717d42
    Andrea Arcangeli authored
    Patch series "reapply: relax __GFP_THISNODE for MADV_HUGEPAGE mappings".
    
    The fixes for what was originally reported as "pathological THP
    behavior" we rightfully reverted to be sure not to introduced
    regressions at end of a merge window after a severe regression report
    from the kernel bot.  We can safely re-apply them now that we had time
    to analyze the problem.
    
    The mm process worked fine, because the good fixes were eventually
    committed upstream without excessive delay.
    
    The regression reported by the kernel bot however forced us to revert
    the good fixes to be sure not to introduce regressions and to give us
    the time to analyze the issue further.  The silver lining is that this
    extra time allowed to think more at this issue and also plan for a
    future direction to improve things further in terms of THP NUMA
    locality.
    
    This patch (of 2):
    
    This reverts commit 356ff8a9 ("Revert "mm, thp: consolidate THP
    gfp handling into alloc_hugepage_direct_gfpmask").  So it reapplies
    89c83fb5 ("mm, thp: consolidate THP gfp handling into
    alloc_hugepage_direct_gfpmask").
    
    Consolidation of the THP allocation flags at the same place was meant to
    be a clean up to easier handle otherwise scattered code which is
    imposing a maintenance burden.  There were no real problems observed
    with the gfp mask consolidation but the reversion was rushed through
    without a larger consensus regardless.
    
    This patch brings the consolidation back because this should make the
    long term maintainability easier as well as it should allow future
    changes to be less error prone.
    
    [mhocko@kernel.org: changelog additions]
    Link: http://lkml.kernel.org/r/20190503223146.2312-2-aarcange@redhat.com
    
    
    Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
    Acked-by: default avatarMichal Hocko <mhocko@suse.com>
    Cc: Mel Gorman <mgorman@techsingularity.net>
    Cc: Vlastimil Babka <vbabka@suse.cz>
    Cc: David Rientjes <rientjes@google.com>
    Cc: Zi Yan <zi.yan@cs.rutgers.edu>
    Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
    Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    92717d42