On Wed, Jul 19, 2023 at 3:53 PM Andres Freund <
andres@anarazel.de> wrote:
>
> Hi,
>
> David and I were chatting about this patch, in the context of his bump
> allocator patch. Attached is a rebased version that is also split up into two
> steps, and a bit more polished.
Here is a quick test -- something similar was used to measure the slab improvements last cycle. With radix tree v37 0001-0011 from [1],
create extension bench_radix_tree;
select avg(load_ms) from generate_series(1,100) x(x), lateral (select * from bench_load_random_int(100 * 1000 * (1+x-x))) a;
The backend was pinned and turbo off. Perf runs were separate from timed runs. I included 0002 for completeness.
v37
avg
---------------------
27.0400000000000000
32.42% postgres bench_radix_tree.so [.] rt_recursive_set
21.60% postgres postgres [.] SlabAlloc
11.06% postgres [unknown] [k] 0xffffffff930018f7
10.49% postgres bench_radix_tree.so [.] rt_extend_down
7.07% postgres postgres [.] MemoryContextAlloc
4.83% postgres bench_radix_tree.so [.] rt_node_insert_inner
2.19% postgres bench_radix_tree.so [.] rt_grow_node_48
2.16% postgres bench_radix_tree.so [.] rt_set.isra.0
1.50% postgres bench_radix_tree.so [.] MemoryContextAlloc@plt
v37 + palloc sibling calls
avg
---------------------
26.0700000000000000
v37 + palloc sibling calls + opt aset
avg
---------------------
26.0900000000000000
33.78% postgres bench_radix_tree.so [.] rt_recursive_set
23.04% postgres postgres [.] SlabAlloc
11.43% postgres [unknown] [k] 0xffffffff930018f7
11.05% postgres bench_radix_tree.so [.] rt_extend_down
5.52% postgres bench_radix_tree.so [.] rt_node_insert_inner
2.47% postgres bench_radix_tree.so [.] rt_set.isra.0
2.30% postgres bench_radix_tree.so [.] rt_grow_node_48
1.88% postgres postgres [.] MemoryContextAlloc
1.44% postgres bench_radix_tree.so [.] MemoryContextAlloc@plt
It's nice to see MemoryContextAlloc go down in the profile.
