Messages in this thread | | | From | Mel Gorman <> | Subject | [PATCH 0/5] Follow-up on high-order PCP caching | Date | Tue, 15 Feb 2022 14:51:06 +0000 |
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Commit 44042b449872 ("mm/page_alloc: allow high-order pages to be stored on the per-cpu lists") was primarily aimed at reducing the cost of SLUB cache refills of high-order pages in two ways. Firstly, zone lock acquisitions was reduced and secondly, there were fewer buddy list modifications. This is a follow-up series fixing some issues that became apparant after merging.
Patch 1 is a functional fix. It's harmless but inefficient.
Patches 2-4 reduce the overhead of bulk freeing of PCP pages. While the overhead is small, it's cumulative and noticable when truncating large files. The changelog for patch 4 includes results of a microbench that deletes large sparse files with data in page cache. Sparse files were used to eliminate filesystem overhead.
Patch 5 addresses issues with high-order PCP pages being stored on PCP lists for too long. Pages freed on a CPU potentially may not be quickly reused and in some cases this can increase cache miss rates. Details are included in the changelog.
mm/page_alloc.c | 128 ++++++++++++++++++++++++------------------------ 1 file changed, 64 insertions(+), 64 deletions(-)
-- 2.31.1
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