Optimize zap.Any to use less memory on stack (intermediate props verion) #1308

rabbbit · 2023-07-30T03:44:19Z

This is an alternative to:

Improve Any stack usage #1301 and Improve Any stack usage #1302 and Improve Any stack usage #1304 - a series of PRs that are faster than this one. However, they rely on unsafe.
Optimize zap.Any to allocate less memory on stack #1303 - my own PR that uses closures, to reduce the stack size by 60%.
Optimize zap.Any to use less memory on stack (inline version) #1305 - my own PR that inline bunch of loops
https://github.com/uber-go/zap/compare/pawel/any-int5 that does the same as above, but is slightly easier to parse
Reduce Any stack usage with map + list of lookups #1307 - a reflect.TypeOf lookup version

THIS PR IS INCOMPLETE - it shows a possible approach, but I wanted to get reviewers thoughts before typing everything in.

I originally thought we can use a type props strucy intermediary struct to store the data, but that hits the same problem: every props would get it's own slot on the stack. This avoids this by returning the raw data.

Pros:

the implementation is shared between Any and strongly typed Fields
no reflect or unsafe
reduced the stack significantly - we should be able to get to the same ~180 bytes as ~1305.
no peft penalty for strongly typed versions, at least on ARM64 it's compiled away.

Cons:

the code gets a bit harder to maintain. It's significantly better than Optimize zap.Any to use less memory on stack (inline version) #1305 I would say though.

codecov · 2023-07-30T03:53:07Z

Codecov Report

Merging #1308 (dd358dd) into master (ae3953e) will increase coverage by 0.02%.
The diff coverage is 100.00%.

❗ Current head dd358dd differs from pull request most recent head 09fee60. Consider uploading reports for the commit 09fee60 to get more accurate results

@@            Coverage Diff             @@
##           master    #1308      +/-   ##
==========================================
+ Coverage   98.08%   98.11%   +0.02%     
==========================================
  Files          50       50              
  Lines        3242     3281      +39     
==========================================
+ Hits         3180     3219      +39     
  Misses         53       53              
  Partials        9        9

Files Changed	Coverage Δ
field.go	`100.00% <100.00%> (ø)`

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@prashantv

This is a prefactor for #1301, #1302, #1304, #1305, #1307, #1308 and #1310. We're writing various approaches to reduce the stock size and it's painful to keep copy-pasting the tests between PRs. This was suggested in @prashantv in #1307. The tests are mostly based on tests in #1303, but made "more generic", as #1307 we might want to test across more than just a single type. It does make the tests a bit harder to setup. Some of the setup is inconvenient (we duplicate the value in both `typed` and `any` version of the tests) but hopefully okay to understand. A fully non-duplicated alternative would likely require something like #1310 itself. For #1307 in particular a test against interface type would likely be needed, so adding it here too. The tests compare two code paths, with the same arguments, one using a strongly typed method and second using `zap.Any`. We have: - a simple "create field" case for a baseline - a "create and log" case for a realistic case (we typically log the fields) - a "create and log in a goroutine" case for the pathological case we're trying to solve for. - a "create and long in goroutine in a pre-warmed system" that does the above, but before tries to affect the starting goroutine stack size to provide an realistic example. Without this, for any tests with 2+ goroutines, the cost of `zap.Any` is not visible, as we always end up expanding the stack even in the strongly typed methods. The test results are: ``` goos: darwin goarch: arm64 pkg: go.uber.org/zap BenchmarkAny/string-typ-no-logger 166879518 6.988 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-typ-no-logger-12 167398297 6.973 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-any-no-logger 87669631 13.97 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-any-no-logger-12 86760837 14.11 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-typ-logger 3059485 395.5 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-typ-logger-12 3141176 379.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-any-logger 2995699 401.3 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-any-logger-12 3071046 391.1 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-typ-logger-go 784323 1351 ns/op 146 B/op 2 allocs/op BenchmarkAny/string-typ-logger-go-12 2000835 613.9 ns/op 96 B/op 2 allocs/op BenchmarkAny/string-any-logger-go 477486 2479 ns/op 117 B/op 2 allocs/op BenchmarkAny/string-any-logger-go-12 1830955 680.0 ns/op 112 B/op 2 allocs/op BenchmarkAny/string-typ-logger-go-stack 841566 1328 ns/op 96 B/op 2 allocs/op BenchmarkAny/string-typ-logger-go-stack-12 2625226 479.6 ns/op 96 B/op 2 allocs/op BenchmarkAny/string-any-logger-go-stack 486084 2493 ns/op 112 B/op 2 allocs/op BenchmarkAny/string-any-logger-go-stack-12 2658640 667.9 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-typ-no-logger 147314238 8.034 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-typ-no-logger-12 157857937 7.436 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-any-no-logger 58872349 20.19 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-any-no-logger-12 60532305 20.27 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-typ-logger 3094204 411.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-typ-logger-12 3163489 383.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-any-logger 2981940 427.2 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-any-logger-12 2777792 394.0 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-typ-logger-go 911761 1335 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-typ-logger-go-12 2006440 605.2 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go 467934 2518 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go-12 1786076 683.1 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-typ-logger-go-stack 855794 1316 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-typ-logger-go-stack-12 2598783 434.5 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go-stack 473282 2474 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go-stack-12 2020183 651.9 ns/op 112 B/op 2 allocs/op PASS ok go.uber.org/zap 53.516s ```

@prashantv

This is a prefactor for #1301, #1302, #1304, #1305, #1307, #1308 and #1310. We're writing various approaches to reduce the stock size and it's painful to keep copy-pasting the tests between PRs. This was suggested in @prashantv in #1307. The tests are mostly based on tests in #1303, but made "more generic", as #1307 we might want to test across more than just a single type. It does make the tests a bit harder to setup. Some of the setup is inconvenient (we duplicate the value in both `typed` and `any` version of the tests) but hopefully okay to understand. A fully non-duplicated alternative would likely require something like #1310 itself. For #1307 in particular a test against interface type would likely be needed, so adding it here too. The tests compare two code paths, with the same arguments, one using a strongly typed method and second using `zap.Any`. We have: - a simple "create field" case for a baseline - a "create and log" case for a realistic case (we typically log the fields) - a "create and log in a goroutine" case for the pathological case we're trying to solve for. - -a "create and long in goroutine in a pre-warmed system" that does the above- we decided it's not worth the complication. The test results are: ``` ❯ go test -bench BenchmarkAny -benchmem -cpu 1 goos: darwin goarch: arm64 pkg: go.uber.org/zap BenchmarkAny/string/field-only/typed 161981473 7.374 ns/op 0 B/op 0 allocs/op BenchmarkAny/string/field-only/any 82343354 14.67 ns/op 0 B/op 0 allocs/op BenchmarkAny/string/log/typed 2965648 416.1 ns/op 64 B/op 1 allocs/op BenchmarkAny/string/log/any 2920292 418.8 ns/op 64 B/op 1 allocs/op BenchmarkAny/string/log-go/typed 1000000 1158 ns/op 112 B/op 3 allocs/op BenchmarkAny/string/log-go/any 553144 2152 ns/op 128 B/op 3 allocs/op BenchmarkAny/stringer/field-only/typed 160509367 7.548 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer/field-only/any 51330402 23.45 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer/log/typed 3221404 377.0 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer/log/any 2726443 393.5 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer/log-go/typed 1000000 1129 ns/op 112 B/op 3 allocs/op BenchmarkAny/stringer/log-go/any 558602 2147 ns/op 128 B/op 3 allocs/op PASS ok go.uber.org/zap 19.426s ``` On gotip: ``` ❯ gotip test -bench BenchmarkAny -benchmem -cpu 1 goos: darwin goarch: arm64 pkg: go.uber.org/zap BenchmarkAny/string/field-only/typed 155084869 7.603 ns/op 0 B/op 0 allocs/op BenchmarkAny/string/field-only/any 82740788 14.55 ns/op 0 B/op 0 allocs/op BenchmarkAny/string/log/typed 2800495 411.6 ns/op 64 B/op 1 allocs/op BenchmarkAny/string/log/any 2896258 411.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/string/log-go/typed 1000000 1155 ns/op 112 B/op 3 allocs/op BenchmarkAny/string/log-go/any 551599 2168 ns/op 128 B/op 3 allocs/op BenchmarkAny/stringer/field-only/typed 159505488 7.578 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer/field-only/any 51406354 23.78 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer/log/typed 3011210 388.6 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer/log/any 3010370 395.1 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer/log-go/typed 1000000 1161 ns/op 112 B/op 3 allocs/op BenchmarkAny/stringer/log-go/any 553860 2161 ns/op 128 B/op 3 allocs/op PASS ok go.uber.org/zap 19.391s ``` on amd64 (similar, 2x worse stack growth impact) ``` % go test -bench BenchmarkAny -benchmem -cpu 1 goos: linux goarch: amd64 pkg: go.uber.org/zap cpu: AMD EPYC 7B13 BenchmarkAny/string/field-only/typed 47534053 25.23 ns/op 0 B/op 0 allocs/op BenchmarkAny/string/field-only/any 36913526 32.57 ns/op 0 B/op 0 allocs/op BenchmarkAny/string/log/typed 1693508 725.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/string/log/any 1576172 765.3 ns/op 64 B/op 1 allocs/op BenchmarkAny/string/log-go/typed 516832 2343 ns/op 112 B/op 3 allocs/op BenchmarkAny/string/log-go/any 243692 4404 ns/op 128 B/op 3 allocs/op BenchmarkAny/stringer/field-only/typed 48735537 24.73 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer/field-only/any 26115684 47.24 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer/log/typed 1761630 677.5 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer/log/any 1646913 705.4 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer/log-go/typed 534187 2275 ns/op 112 B/op 3 allocs/op BenchmarkAny/stringer/log-go/any 273787 4348 ns/op 128 B/op 3 allocs/op PASS ok go.uber.org/zap 18.890s ```

…ion) This is an alternative to: - #1301 and #1302 and #1304 - a series of PRs that are faster than this one. However, they rely on unsafe. - #1303 - my own PR that uses closures, to reduce the stack size by 60%. - #1305 - my own PR that inline bunch of loops - https://github.com/uber-go/zap/compare/pawel/any-int5 that does the same as above, but is slightly easier to parse - #1307 - a reflect.TypeOf lookup version THIS PR IS INCOMPLETE - it shows a possible approach, but I wanted to get reviewers thoughts before typing everything in. I originally thought we can use a `type props strucy` intermediary struct to store the data, but that hits the same problem: every `props` would get it's own slot on the stack. This avoids this by returning the raw data. Pros: - the implementation is shared between `Any` and strongly typed Fields - no reflect or unsafe - reduced the stack significantly - we should be able to get to the same ~180 bytes as ~1305. - no peft penalty for strongly typed versions, at least on ARM64 it's compiled away. Cons: - the code gets a bit harder to maintain. It's significantly better than #1305 I would say though.

rabbbit · 2023-08-01T03:11:45Z

Closed in favor of #1310.

Yet another attempt at reducing the stack size of zap.Any, borrowing from #1301, #1303, #1304, #1305, #1307, and #1308. This approach defines a generic data type for field constructors of a specific type. This is similar to the lookup map in #1307, minus the map lookup, the interface match, or reflection. type anyFieldC[T any] func(string, T) Field The generic data type provides a non-generic method matching the interface: interface{ Any(string, any) Field } **Stack size**: The stack size of zap.Any following this change is 0xc0 (192 bytes). % go build -gcflags -S 2>&1 | grep ^go.uber.org/zap.Any go.uber.org/zap.Any STEXT size=5861 args=0x20 locals=0xc0 funcid=0x0 align=0x0 This is just 8 bytes more than #1305, which is the smallest stack size of all other attempts. **Allocations**: Everything appears to get inlined with no heap escapes: % go build -gcflags -m 2>&1 | grep field.go | perl -n -e 'next unless m{^./field.go:(\d+)}; print if ($1 >= 413)' | grep 'escapes' [no output] (Line 413 declares anyFieldC) Besides that, the output of `-m` for the relevant section of code consists of almost entirely: ./field.go:415:6: can inline anyFieldC[go.shape.bool].Any ./field.go:415:6: can inline anyFieldC[go.shape.[]bool].Any ./field.go:415:6: can inline anyFieldC[go.shape.complex128].Any [...] ./field.go:415:6: inlining call to anyFieldC[go.shape.complex128].Any ./field.go:415:6: inlining call to anyFieldC[go.shape.[]bool].Any ./field.go:415:6: inlining call to anyFieldC[go.shape.bool].Any Followed by: ./field.go:428:10: leaking param: key ./field.go:428:22: leaking param: value **Maintainability**: Unlike some of the other approaches, this variant is more maintainable. The `zap.Any` function looks roughly the same. Adding new branches there is obvious, and requires no duplication. **Performance**: This is a net improvement against master on BenchmarkAny's log-go checks that log inside a new goroutine. ``` name old time/op new time/op delta Any/string/field-only/typed 25.2ns ± 1% 25.6ns ± 2% ~ (p=0.460 n=5+5) Any/string/field-only/any 56.9ns ± 3% 79.4ns ± 0% +39.55% (p=0.008 n=5+5) Any/string/log/typed 1.47µs ± 0% 1.49µs ± 4% +1.58% (p=0.016 n=4+5) Any/string/log/any 1.53µs ± 2% 1.55µs ± 1% +1.37% (p=0.016 n=5+5) Any/string/log-go/typed 5.97µs ± 6% 5.99µs ± 1% ~ (p=0.151 n=5+5) Any/string/log-go/any 10.9µs ± 0% 6.2µs ± 0% -43.32% (p=0.008 n=5+5) Any/stringer/field-only/typed 25.3ns ± 1% 25.5ns ± 1% +1.09% (p=0.008 n=5+5) Any/stringer/field-only/any 85.5ns ± 1% 124.5ns ± 0% +45.66% (p=0.008 n=5+5) Any/stringer/log/typed 1.43µs ± 1% 1.42µs ± 2% ~ (p=0.175 n=4+5) Any/stringer/log/any 1.50µs ± 1% 1.56µs ± 6% +4.20% (p=0.008 n=5+5) Any/stringer/log-go/typed 5.94µs ± 0% 5.92µs ± 0% -0.40% (p=0.032 n=5+5) Any/stringer/log-go/any 11.1µs ± 2% 6.3µs ± 0% -42.93% (p=0.008 n=5+5) name old alloc/op new alloc/op delta Any/string/field-only/typed 0.00B 0.00B ~ (all equal) Any/string/field-only/any 0.00B 0.00B ~ (all equal) Any/string/log/typed 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/string/log/any 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/string/log-go/typed 112B ± 0% 112B ± 0% ~ (all equal) Any/string/log-go/any 128B ± 0% 128B ± 0% ~ (all equal) Any/stringer/field-only/typed 0.00B 0.00B ~ (all equal) Any/stringer/field-only/any 0.00B 0.00B ~ (all equal) Any/stringer/log/typed 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/stringer/log/any 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/stringer/log-go/typed 112B ± 0% 112B ± 0% ~ (all equal) Any/stringer/log-go/any 128B ± 0% 128B ± 0% ~ (all equal) name old allocs/op new allocs/op delta Any/string/field-only/typed 0.00 0.00 ~ (all equal) Any/string/field-only/any 0.00 0.00 ~ (all equal) Any/string/log/typed 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/string/log/any 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/string/log-go/typed 3.00 ± 0% 3.00 ± 0% ~ (all equal) Any/string/log-go/any 3.00 ± 0% 3.00 ± 0% ~ (all equal) Any/stringer/field-only/typed 0.00 0.00 ~ (all equal) Any/stringer/field-only/any 0.00 0.00 ~ (all equal) Any/stringer/log/typed 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/stringer/log/any 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/stringer/log-go/typed 3.00 ± 0% 3.00 ± 0% ~ (all equal) Any/stringer/log-go/any 3.00 ± 0% 3.00 ± 0% ~ (all equal) ``` It causes a regression in "field-only" which calls the field constructor and discards the result without using it in a logger. I believe this is acceptable because that's not a real use case; we expect the result to be used with a logger.

@prashantv

This is a prefactor for #1301, #1302, #1304, #1305, #1307, #1308 and #1310. We're writing various approaches to reduce the stack size and it's painful to keep copy-pasting the tests between PRs. This was suggested in @prashantv in #1307. The tests are mostly based on tests in #1303, but made "more generic", as #1307 we might want to test across more than just a single type. It does make the tests a bit harder to setup. Some of the setup is inconvenient (we duplicate the value in both `typed` and `any` version of the tests) but hopefully okay to understand. A fully non-duplicated alternative would likely require something like #1310 itself. For #1307 in particular a test against interface type would likely be needed, so adding it here too. The tests compare two code paths, with the same arguments, one using a strongly typed method and second using `zap.Any`. We have: - a simple "create field" case for a baseline - a "create and log" case for a realistic case (we typically log the fields) - a "create and log in a goroutine" case for the pathological case we're trying to solve for. - a "create and long in goroutine in a pre-warmed system" that does the above, but before tries to affect the starting goroutine stack size to provide an realistic example. Without this, for any tests with 2+ goroutines, the cost of `zap.Any` is not visible, as we always end up expanding the stack even in the strongly typed methods. The test results are: ``` goos: darwin goarch: arm64 pkg: go.uber.org/zap BenchmarkAny/string-typ-no-logger 166879518 6.988 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-typ-no-logger-12 167398297 6.973 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-any-no-logger 87669631 13.97 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-any-no-logger-12 86760837 14.11 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-typ-logger 3059485 395.5 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-typ-logger-12 3141176 379.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-any-logger 2995699 401.3 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-any-logger-12 3071046 391.1 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-typ-logger-go 784323 1351 ns/op 146 B/op 2 allocs/op BenchmarkAny/string-typ-logger-go-12 2000835 613.9 ns/op 96 B/op 2 allocs/op BenchmarkAny/string-any-logger-go 477486 2479 ns/op 117 B/op 2 allocs/op BenchmarkAny/string-any-logger-go-12 1830955 680.0 ns/op 112 B/op 2 allocs/op BenchmarkAny/string-typ-logger-go-stack 841566 1328 ns/op 96 B/op 2 allocs/op BenchmarkAny/string-typ-logger-go-stack-12 2625226 479.6 ns/op 96 B/op 2 allocs/op BenchmarkAny/string-any-logger-go-stack 486084 2493 ns/op 112 B/op 2 allocs/op BenchmarkAny/string-any-logger-go-stack-12 2658640 667.9 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-typ-no-logger 147314238 8.034 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-typ-no-logger-12 157857937 7.436 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-any-no-logger 58872349 20.19 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-any-no-logger-12 60532305 20.27 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-typ-logger 3094204 411.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-typ-logger-12 3163489 383.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-any-logger 2981940 427.2 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-any-logger-12 2777792 394.0 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-typ-logger-go 911761 1335 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-typ-logger-go-12 2006440 605.2 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go 467934 2518 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go-12 1786076 683.1 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-typ-logger-go-stack 855794 1316 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-typ-logger-go-stack-12 2598783 434.5 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go-stack 473282 2474 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go-stack-12 2020183 651.9 ns/op 112 B/op 2 allocs/op PASS ok go.uber.org/zap 53.516s ```

Yet another attempt at reducing the stack size of zap.Any, borrowing from #1301, #1303, #1304, #1305, #1307, and #1308. This approach defines a generic data type for field constructors of a specific type. This is similar to the lookup map in #1307, minus the map lookup, the interface match, or reflection. type anyFieldC[T any] func(string, T) Field The generic data type provides a non-generic method matching the interface: interface{ Any(string, any) Field } **Stack size**: The stack size of zap.Any following this change is 0xc0 (192 bytes). % go build -gcflags -S 2>&1 | grep ^go.uber.org/zap.Any go.uber.org/zap.Any STEXT size=5861 args=0x20 locals=0xc0 funcid=0x0 align=0x0 This is just 8 bytes more than #1305, which is the smallest stack size of all other attempts. **Allocations**: Everything appears to get inlined with no heap escapes: % go build -gcflags -m 2>&1 | grep field.go | perl -n -e 'next unless m{^./field.go:(\d+)}; print if ($1 >= 413)' | grep 'escapes' [no output] (Line 413 declares anyFieldC) Besides that, the output of `-m` for the relevant section of code consists of almost entirely: ./field.go:415:6: can inline anyFieldC[go.shape.bool].Any ./field.go:415:6: can inline anyFieldC[go.shape.[]bool].Any ./field.go:415:6: can inline anyFieldC[go.shape.complex128].Any [...] ./field.go:415:6: inlining call to anyFieldC[go.shape.complex128].Any ./field.go:415:6: inlining call to anyFieldC[go.shape.[]bool].Any ./field.go:415:6: inlining call to anyFieldC[go.shape.bool].Any Followed by: ./field.go:428:10: leaking param: key ./field.go:428:22: leaking param: value **Maintainability**: Unlike some of the other approaches, this variant is more maintainable. The `zap.Any` function looks roughly the same. Adding new branches there is obvious, and requires no duplication. **Performance**: This is a net improvement against master on BenchmarkAny's log-go checks that log inside a new goroutine. ``` name old time/op new time/op delta Any/string/field-only/typed 25.2ns ± 1% 25.6ns ± 2% ~ (p=0.460 n=5+5) Any/string/field-only/any 56.9ns ± 3% 79.4ns ± 0% +39.55% (p=0.008 n=5+5) Any/string/log/typed 1.47µs ± 0% 1.49µs ± 4% +1.58% (p=0.016 n=4+5) Any/string/log/any 1.53µs ± 2% 1.55µs ± 1% +1.37% (p=0.016 n=5+5) Any/string/log-go/typed 5.97µs ± 6% 5.99µs ± 1% ~ (p=0.151 n=5+5) Any/string/log-go/any 10.9µs ± 0% 6.2µs ± 0% -43.32% (p=0.008 n=5+5) Any/stringer/field-only/typed 25.3ns ± 1% 25.5ns ± 1% +1.09% (p=0.008 n=5+5) Any/stringer/field-only/any 85.5ns ± 1% 124.5ns ± 0% +45.66% (p=0.008 n=5+5) Any/stringer/log/typed 1.43µs ± 1% 1.42µs ± 2% ~ (p=0.175 n=4+5) Any/stringer/log/any 1.50µs ± 1% 1.56µs ± 6% +4.20% (p=0.008 n=5+5) Any/stringer/log-go/typed 5.94µs ± 0% 5.92µs ± 0% -0.40% (p=0.032 n=5+5) Any/stringer/log-go/any 11.1µs ± 2% 6.3µs ± 0% -42.93% (p=0.008 n=5+5) name old alloc/op new alloc/op delta Any/string/field-only/typed 0.00B 0.00B ~ (all equal) Any/string/field-only/any 0.00B 0.00B ~ (all equal) Any/string/log/typed 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/string/log/any 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/string/log-go/typed 112B ± 0% 112B ± 0% ~ (all equal) Any/string/log-go/any 128B ± 0% 128B ± 0% ~ (all equal) Any/stringer/field-only/typed 0.00B 0.00B ~ (all equal) Any/stringer/field-only/any 0.00B 0.00B ~ (all equal) Any/stringer/log/typed 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/stringer/log/any 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/stringer/log-go/typed 112B ± 0% 112B ± 0% ~ (all equal) Any/stringer/log-go/any 128B ± 0% 128B ± 0% ~ (all equal) name old allocs/op new allocs/op delta Any/string/field-only/typed 0.00 0.00 ~ (all equal) Any/string/field-only/any 0.00 0.00 ~ (all equal) Any/string/log/typed 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/string/log/any 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/string/log-go/typed 3.00 ± 0% 3.00 ± 0% ~ (all equal) Any/string/log-go/any 3.00 ± 0% 3.00 ± 0% ~ (all equal) Any/stringer/field-only/typed 0.00 0.00 ~ (all equal) Any/stringer/field-only/any 0.00 0.00 ~ (all equal) Any/stringer/log/typed 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/stringer/log/any 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/stringer/log-go/typed 3.00 ± 0% 3.00 ± 0% ~ (all equal) Any/stringer/log-go/any 3.00 ± 0% 3.00 ± 0% ~ (all equal) ``` It causes a regression in "field-only" which calls the field constructor and discards the result without using it in a logger. I believe this is acceptable because that's not a real use case; we expect the result to be used with a logger.

@prashantv

This is a prefactor for #1301, #1302, #1304, #1305, #1307, #1308 and #1310. We're writing various approaches to reduce the stock size and it's painful to keep copy-pasting the tests between PRs. This was suggested in @prashantv in #1307. The tests are mostly based on tests in #1303, but made "more generic", as #1307 we might want to test across more than just a single type. It does make the tests a bit harder to setup. Some of the setup is inconvenient (we duplicate the value in both `typed` and `any` version of the tests) but hopefully okay to understand. A fully non-duplicated alternative would likely require something like #1310 itself. For #1307 in particular a test against interface type would likely be needed, so adding it here too. The tests compare two code paths, with the same arguments, one using a strongly typed method and second using `zap.Any`. We have: - a simple "create field" case for a baseline - a "create and log" case for a realistic case (we typically log the fields) - a "create and log in a goroutine" case for the pathological case we're trying to solve for. - a "create and long in goroutine in a pre-warmed system" that does the above, but before tries to affect the starting goroutine stack size to provide an realistic example. Without this, for any tests with 2+ goroutines, the cost of `zap.Any` is not visible, as we always end up expanding the stack even in the strongly typed methods. The test results are: ``` goos: darwin goarch: arm64 pkg: go.uber.org/zap BenchmarkAny/string-typ-no-logger 166879518 6.988 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-typ-no-logger-12 167398297 6.973 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-any-no-logger 87669631 13.97 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-any-no-logger-12 86760837 14.11 ns/op 0 B/op 0 allocs/op BenchmarkAny/string-typ-logger 3059485 395.5 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-typ-logger-12 3141176 379.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-any-logger 2995699 401.3 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-any-logger-12 3071046 391.1 ns/op 64 B/op 1 allocs/op BenchmarkAny/string-typ-logger-go 784323 1351 ns/op 146 B/op 2 allocs/op BenchmarkAny/string-typ-logger-go-12 2000835 613.9 ns/op 96 B/op 2 allocs/op BenchmarkAny/string-any-logger-go 477486 2479 ns/op 117 B/op 2 allocs/op BenchmarkAny/string-any-logger-go-12 1830955 680.0 ns/op 112 B/op 2 allocs/op BenchmarkAny/string-typ-logger-go-stack 841566 1328 ns/op 96 B/op 2 allocs/op BenchmarkAny/string-typ-logger-go-stack-12 2625226 479.6 ns/op 96 B/op 2 allocs/op BenchmarkAny/string-any-logger-go-stack 486084 2493 ns/op 112 B/op 2 allocs/op BenchmarkAny/string-any-logger-go-stack-12 2658640 667.9 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-typ-no-logger 147314238 8.034 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-typ-no-logger-12 157857937 7.436 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-any-no-logger 58872349 20.19 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-any-no-logger-12 60532305 20.27 ns/op 0 B/op 0 allocs/op BenchmarkAny/stringer-typ-logger 3094204 411.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-typ-logger-12 3163489 383.7 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-any-logger 2981940 427.2 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-any-logger-12 2777792 394.0 ns/op 64 B/op 1 allocs/op BenchmarkAny/stringer-typ-logger-go 911761 1335 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-typ-logger-go-12 2006440 605.2 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go 467934 2518 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go-12 1786076 683.1 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-typ-logger-go-stack 855794 1316 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-typ-logger-go-stack-12 2598783 434.5 ns/op 96 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go-stack 473282 2474 ns/op 112 B/op 2 allocs/op BenchmarkAny/stringer-any-logger-go-stack-12 2020183 651.9 ns/op 112 B/op 2 allocs/op PASS ok go.uber.org/zap 53.516s ``` reviews rename review farewell, my friend dummy

Yet another attempt at reducing the stack size of zap.Any, borrowing from #1301, #1303, #1304, #1305, #1307, and #1308. This approach defines a generic data type for field constructors of a specific type. This is similar to the lookup map in #1307, minus the map lookup, the interface match, or reflection. type anyFieldC[T any] func(string, T) Field The generic data type provides a non-generic method matching the interface: interface{ Any(string, any) Field } **Stack size**: The stack size of zap.Any following this change is 0xc0 (192 bytes). % go build -gcflags -S 2>&1 | grep ^go.uber.org/zap.Any go.uber.org/zap.Any STEXT size=5861 args=0x20 locals=0xc0 funcid=0x0 align=0x0 This is just 8 bytes more than #1305, which is the smallest stack size of all other attempts. **Allocations**: Everything appears to get inlined with no heap escapes: % go build -gcflags -m 2>&1 | grep field.go | perl -n -e 'next unless m{^./field.go:(\d+)}; print if ($1 >= 413)' | grep 'escapes' [no output] (Line 413 declares anyFieldC) Besides that, the output of `-m` for the relevant section of code consists of almost entirely: ./field.go:415:6: can inline anyFieldC[go.shape.bool].Any ./field.go:415:6: can inline anyFieldC[go.shape.[]bool].Any ./field.go:415:6: can inline anyFieldC[go.shape.complex128].Any [...] ./field.go:415:6: inlining call to anyFieldC[go.shape.complex128].Any ./field.go:415:6: inlining call to anyFieldC[go.shape.[]bool].Any ./field.go:415:6: inlining call to anyFieldC[go.shape.bool].Any Followed by: ./field.go:428:10: leaking param: key ./field.go:428:22: leaking param: value **Maintainability**: Unlike some of the other approaches, this variant is more maintainable. The `zap.Any` function looks roughly the same. Adding new branches there is obvious, and requires no duplication. **Performance**: This is a net improvement against master on BenchmarkAny's log-go checks that log inside a new goroutine. ``` name old time/op new time/op delta Any/string/field-only/typed 25.2ns ± 1% 25.6ns ± 2% ~ (p=0.460 n=5+5) Any/string/field-only/any 56.9ns ± 3% 79.4ns ± 0% +39.55% (p=0.008 n=5+5) Any/string/log/typed 1.47µs ± 0% 1.49µs ± 4% +1.58% (p=0.016 n=4+5) Any/string/log/any 1.53µs ± 2% 1.55µs ± 1% +1.37% (p=0.016 n=5+5) Any/string/log-go/typed 5.97µs ± 6% 5.99µs ± 1% ~ (p=0.151 n=5+5) Any/string/log-go/any 10.9µs ± 0% 6.2µs ± 0% -43.32% (p=0.008 n=5+5) Any/stringer/field-only/typed 25.3ns ± 1% 25.5ns ± 1% +1.09% (p=0.008 n=5+5) Any/stringer/field-only/any 85.5ns ± 1% 124.5ns ± 0% +45.66% (p=0.008 n=5+5) Any/stringer/log/typed 1.43µs ± 1% 1.42µs ± 2% ~ (p=0.175 n=4+5) Any/stringer/log/any 1.50µs ± 1% 1.56µs ± 6% +4.20% (p=0.008 n=5+5) Any/stringer/log-go/typed 5.94µs ± 0% 5.92µs ± 0% -0.40% (p=0.032 n=5+5) Any/stringer/log-go/any 11.1µs ± 2% 6.3µs ± 0% -42.93% (p=0.008 n=5+5) name old alloc/op new alloc/op delta Any/string/field-only/typed 0.00B 0.00B ~ (all equal) Any/string/field-only/any 0.00B 0.00B ~ (all equal) Any/string/log/typed 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/string/log/any 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/string/log-go/typed 112B ± 0% 112B ± 0% ~ (all equal) Any/string/log-go/any 128B ± 0% 128B ± 0% ~ (all equal) Any/stringer/field-only/typed 0.00B 0.00B ~ (all equal) Any/stringer/field-only/any 0.00B 0.00B ~ (all equal) Any/stringer/log/typed 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/stringer/log/any 64.0B ± 0% 64.0B ± 0% ~ (all equal) Any/stringer/log-go/typed 112B ± 0% 112B ± 0% ~ (all equal) Any/stringer/log-go/any 128B ± 0% 128B ± 0% ~ (all equal) name old allocs/op new allocs/op delta Any/string/field-only/typed 0.00 0.00 ~ (all equal) Any/string/field-only/any 0.00 0.00 ~ (all equal) Any/string/log/typed 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/string/log/any 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/string/log-go/typed 3.00 ± 0% 3.00 ± 0% ~ (all equal) Any/string/log-go/any 3.00 ± 0% 3.00 ± 0% ~ (all equal) Any/stringer/field-only/typed 0.00 0.00 ~ (all equal) Any/stringer/field-only/any 0.00 0.00 ~ (all equal) Any/stringer/log/typed 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/stringer/log/any 1.00 ± 0% 1.00 ± 0% ~ (all equal) Any/stringer/log-go/typed 3.00 ± 0% 3.00 ± 0% ~ (all equal) Any/stringer/log-go/any 3.00 ± 0% 3.00 ± 0% ~ (all equal) ``` It causes a regression in "field-only" which calls the field constructor and discards the result without using it in a logger. I believe this is acceptable because that's not a real use case; we expect the result to be used with a logger.

rabbbit force-pushed the pawel/any-int6 branch from 0857c9f to dd358dd Compare July 30, 2023 03:52

abhinav mentioned this pull request Jul 30, 2023

zap.Any: Reduce stack size with generics #1310

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rabbbit mentioned this pull request Jul 30, 2023

zap.Any add benchmarks #1311

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rabbbit force-pushed the pawel/any-int6 branch from dd358dd to 09fee60 Compare August 1, 2023 03:10

rabbbit closed this Aug 1, 2023

rabbbit deleted the pawel/any-int6 branch August 2, 2023 02:32

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Optimize zap.Any to use less memory on stack (intermediate props verion) #1308

Optimize zap.Any to use less memory on stack (intermediate props verion) #1308

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Optimize zap.Any to use less memory on stack (intermediate props verion) #1308

Optimize zap.Any to use less memory on stack (intermediate props verion) #1308

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