Replacing boost::container::small_vector

[hkaiser]

This removes the dependency on boost::container::small_vector

Working towards #3440

[msimberg]

Neat, thanks! I don't have any in-depth comments at this point. I'd like to understand how this exactly works, but I don't want that to block this from being merged (I'm happy if it passes tests).

Two questions:

• Is this inspired by: https://cpptelepathy.wordpress.com/2021/10/24/static-vector-in-terms-of-stdvector/?
• How about we put it in hpx::(util::)detail right away?

[hkaiser]

• Is this inspired by: https://cpptelepathy.wordpress.com/2021/10/24/static-vector-in-terms-of-stdvector/?

Yes, that reminded me of some code I had been working on a while back.

• How about we put it in hpx::(util::)detail right away?

ok.

[StellarBot]

Performance test report

HPX Performance

Comparison

BENCHMARK	NO-EXECUTOR
Future Overhead - Create Thread Hierarchical - Latch	+

Info

Property	Before	After
HPX Datetime	2021-08-21T11:38:52+00:00	2021-10-26T22:59:45+00:00
HPX Commit	254db57	c135be8
Envfile
Clustername	daint	daint
Hostname	nid00446	nid00396
Datetime	2021-08-23T15:21:22.855927+02:00	2021-10-27T01:08:05.968118+02:00
Compiler	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0

Comparison

BENCHMARK	FORK_JOIN_EXECUTOR_DEFAULT_FORK_JOIN_POLICY_ALLOCATOR	PARALLEL_EXECUTOR_DEFAULT_PARALLEL_POLICY_ALLOCATOR	SCHEDULER_EXECUTOR_DEFAULT_SCHEDULER_EXECUTOR_ALLOCATOR
Stream Benchmark - Add	(=)	(=)	-
Stream Benchmark - Scale	(=)	(=)	(=)
Stream Benchmark - Triad	(=)	(=)	-
Stream Benchmark - Copy	(=)	(=)	(=)

Info

Property	Before	After
HPX Datetime	2021-10-20T12:40:32+00:00	2021-10-26T22:59:45+00:00
HPX Commit	5ed2694	c135be8
Envfile
Clustername	daint	daint
Hostname	nid01047	nid00396
Datetime	2021-10-21T15:01:27.508281+02:00	2021-10-27T01:08:21.658100+02:00
Compiler	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0

Explanation of Symbols

Symbol	MEANING
=	No performance change (confidence interval within ±1%)
(=)	Probably no performance change (confidence interval within ±2%)
(+)/(-)	Very small performance improvement/degradation (≤1%)
+/-	Small performance improvement/degradation (≤5%)
++/--	Large performance improvement/degradation (≤10%)
+++/---	Very large performance improvement/degradation (>10%)
?	Probably no change, but quite large uncertainty (confidence interval with ±5%)
??	Unclear result, very large uncertainty (±10%)
???	Something unexpected…

[hkaiser]

@msimberg this is ready for review now.

[msimberg]

I think this looks good with my limited knowledge of std::pmr. I've left some questions to check if I've understood things correctly.

[StellarBot]

Performance test report

HPX Performance

Comparison

BENCHMARK	NO-EXECUTOR
Future Overhead - Create Thread Hierarchical - Latch	++

Info

Property	Before	After
HPX Datetime	2021-08-21T11:38:52+00:00	2021-10-28T21:20:27+00:00
HPX Commit	254db57	3ec932b
Datetime	2021-08-23T15:21:22.855927+02:00	2021-10-28T23:38:21.468046+02:00
Envfile
Clustername	daint	daint
Hostname	nid00446	nid00865
Compiler	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0

Comparison

BENCHMARK	FORK_JOIN_EXECUTOR_DEFAULT_FORK_JOIN_POLICY_ALLOCATOR	PARALLEL_EXECUTOR_DEFAULT_PARALLEL_POLICY_ALLOCATOR	SCHEDULER_EXECUTOR_DEFAULT_SCHEDULER_EXECUTOR_ALLOCATOR
Stream Benchmark - Add	-	(=)	(=)
Stream Benchmark - Scale	(=)	(=)	(=)
Stream Benchmark - Triad	-	-	(=)
Stream Benchmark - Copy	(=)	(=)	(=)

Info

Property	Before	After
HPX Datetime	2021-10-22T15:54:13+00:00	2021-10-28T21:20:27+00:00
HPX Commit	916f4d8	3ec932b
Datetime	2021-10-25T11:52:24.316784+02:00	2021-10-28T23:38:36.741595+02:00
Envfile
Clustername	daint	daint
Hostname	nid01196	nid00865
Compiler	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0	/apps/daint/SSL/HPX/packages/llvm-11.0.0/bin/clang++ 11.0.0

Explanation of Symbols

Symbol	MEANING
=	No performance change (confidence interval within ±1%)
(=)	Probably no performance change (confidence interval within ±2%)
(+)/(-)	Very small performance improvement/degradation (≤1%)
+/-	Small performance improvement/degradation (≤5%)
++/--	Large performance improvement/degradation (≤10%)
+++/---	Very large performance improvement/degradation (>10%)
?	Probably no change, but quite large uncertainty (confidence interval with ±5%)
??	Unclear result, very large uncertainty (±10%)
???	Something unexpected…

[msimberg]

We'll need to keep a bit of an eye on the perf tests. However, don't think (hope) that this PR actually affects the timings.

[msimberg]

launch perftests