Feature #5789: Optimize st_table

• Status: Closed
• Assignee: -
• Target version: -

[funny_falcon (Yura Sokolov)]

I prepared couple of patches to optimize st_table performance.

First patch (st_func.patch) is a trivial translation of some macroses to functions,
but it gives ~4% of improvement on gcc-4.5.2 32bit (sorry for not testing other environments).

Second patch (st_pack_table) provides packing for tables sized upto 12 entries.
It gives countable memory footprint reduction and measurable performance improvement
(~8% compared to trunk, ~4% compared to st_func.patch).
Note: synthetic benchmark could show some performance degradation, so that there
could be some exotic workload, which suffer from patch.
But realworld application (and even make check) runs uniformly faster.

Correlated github pull requests are https://github.com/ruby/ruby/pull/70 and https://github.com/ruby/ruby/pull/71

[funny_falcon (Yura Sokolov)]

• File st_pack_tables.patch st_pack_tables.patch added

[funny_falcon (Yura Sokolov)]

• File st_pool_alloc.patch st_pool_alloc.patch added

Another approach to st_table optimization: use lightweight pool allocator for st_table, st_table_entry and bins of smallest size.
http://bugs.ruby-lang.org/attachments/2352/st_pool_alloc.patch

[funny_falcon (Yura Sokolov)]

• File st_pool_alloc_pack.patch st_pool_alloc_pack.patch added

[funny_falcon (Yura Sokolov)]

• File st_pool_alloc_pack.patch st_pool_alloc_pack.patch added

[naruse (Yui NARUSE)]

• Status changed from Open to Closed

Merged in r34309-r34314