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Groups > linux.kernel > #1175830
| From | Vlastimil Babka <vbabka@suse.cz> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [RFC v2 0/4] Outsourcing compaction for THP allocations to kcompactd |
| Date | 2015-07-02 10:50 +0200 |
| Message-ID | <pHIlY-nD-9@gated-at.bofh.it> (permalink) |
| Organization | linux.* mail to news gateway |
This RFC series is another evolution of the attempt to deal with THP allocations latencies. Please see the motivation in the previous version [1] The main difference here is that I've bitten the bullet and implemented per-node kcompactd kthreads - see Patch 1 for the details of why and how. Trying to fit everything into khugepaged was getting too clumsy, and kcompactd could have more benefits, see e.g. the ideas here [2]. Not everything is implemented yet, though, I would welcome some feedback first. The devil will be in the details of course, i.e. how to steer the kcompactd activity. Ideally it should take somehow into account the amount of free memory, its fragmentation, pressure for high-order allocations including hugepages, past successes/failures of compaction, the CPU time spent... not an easy task. Suggestions welcome :) I briefly tested it with mmtests/thpscale, but I don't think the results are that interesting at this moment. The patchset is based on v4.1, next would probably conflict in at least mempolicy.c. I know it's still merge window, but didn't want to delay 2 weeks due to upcoming vacation. Thanks. [1] https://lwn.net/Articles/643891/ [2] http://article.gmane.org/gmane.linux.kernel/1982369 Vlastimil Babka (4): mm, compaction: introduce kcompactd mm, thp: stop preallocating hugepages in khugepaged mm, thp: check for hugepage availability in khugepaged mm, thp: check hugepage availability for fault allocations include/linux/compaction.h | 13 +++ include/linux/mmzone.h | 8 ++ mm/compaction.c | 207 +++++++++++++++++++++++++++++++++++++++++++++ mm/huge_memory.c | 180 +++++++++++++++++++-------------------- mm/internal.h | 39 +++++++++ mm/memory_hotplug.c | 15 ++-- mm/mempolicy.c | 42 +++++---- mm/page_alloc.c | 6 ++ mm/vmscan.c | 7 ++ 9 files changed, 403 insertions(+), 114 deletions(-) -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[RFC v2 0/4] Outsourcing compaction for THP allocations to kcompactd Vlastimil Babka <vbabka@suse.cz> - 2015-07-02 10:50 +0200 [RFC 2/4] mm, thp: stop preallocating hugepages in khugepaged Vlastimil Babka <vbabka@suse.cz> - 2015-07-02 10:50 +0200 [RFC 4/4] mm, thp: check hugepage availability for fault allocations Vlastimil Babka <vbabka@suse.cz> - 2015-07-02 10:50 +0200 [RFC 3/4] mm, thp: check for hugepage availability in khugepaged Vlastimil Babka <vbabka@suse.cz> - 2015-07-02 10:50 +0200 [RFC 1/4] mm, compaction: introduce kcompactd Vlastimil Babka <vbabka@suse.cz> - 2015-07-02 10:50 +0200
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