*: reduce ResetContextOfStmt() and NewRuntimeStatsColl() object allocation #26007
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ti-chi-bot
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Each time we eliminate a allocation from the list, we can reduce the allocation by 2%-1%, and the performance improve a bit. |
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| sc.RuntimeStatsColl = execdetails.NewRuntimeStatsColl() | ||
| // In ExplainFor case, RuntimeStatsColl should not be reset for reuse, | ||
| // because ExplainFor need to display the last statement information. | ||
| if _, ok := s.(*ast.ExplainForStmt); ok { |
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Now I do not reset RuntimeStatsColl when the statement is ExplainFor, the test passes.
| // Reuse the object to reduce allocation when *RuntimeStatsColl is not nil. | ||
| func NewRuntimeStatsColl(reuse *RuntimeStatsColl) *RuntimeStatsColl { | ||
| if reuse != nil { | ||
| for k := range reuse.rootStats { |
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Reuse map is cheaper than create a new map object.
Go compiler optimize this cleanup code pattern to a clearmap() function.
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Temporary close it. |
What problem does this PR solve?
Reduce prepared point get object allocation, see #25573
Set
EnableCollectExecutionInfoconfig to false can reduce the allocation from 101 allocs/op to 89 allocs/op, it does have some performance impact on the point get case @crazycs520What is changed and how it works?
Reduce the allocation rate by 2%
Before:
BenchmarkPreparedPointGet-16 3945436 9160 ns/op 7830 B/op 101 allocs/op
After:
BenchmarkPreparedPointGet-16 4047969 8913 ns/op 7038 B/op 99 allocs/op
What's Changed:
Avoid allocating StatementContext every time, reuse it.
Avoid allocating RuntimeStatsColl every time, reuse it.
How it Works:
Related changes
pingcap/docs/pingcap/docs-cn:Check List
Tests
Release note