231f8c7127
Currently, compaction_capture() does not allow lower-order allocations to
directly capture the movable free pages, even though lower-order
allocations might also be requesting movable pages, that can lead to more
compaction scanning. And, with the enablement of mTHP, such situations
will become more common.
Thus allowing lower-order (mTHP) allocations of movable page types
directly capture the movable free pages can avoid unnecessary compaction
scanning, meanwhile that won't pollute the movable pageblock. With
testing 1M mTHP compaction, it can be seen that compaction scanning is
significantly reduced.
mm-unstable patched
Ops Compaction pages isolated 116598741.00 120946702.00
Ops Compaction migrate scanned 1764870054.00 1488621550.00
Ops Compaction free scanned 7707879039.00 4986299318.00
Ops Compact scan efficiency 22.90 29.85
Ops Compaction cost 73797.69 72933.48
Link: https://lkml.kernel.org/r/8118a5d66a034736a48433beddaca60ed78577c4.1712892329.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.