go/src/runtime/pprof/pprof.go, branch main

runtime/pprof: using buffer writer instead of original writer

2026-04-13T16:24:54Z

Change-Id: Ibff8e7a08090d67d9a0625dee068c8d2eefbd190 GitHub-Last-Rev: b90b986121314615cf5d259d76a7be59303de1b0 GitHub-Pull-Request: golang/go#78630 Reviewed-on: https://go-review.googlesource.com/c/go/+/765480 Reviewed-by: Florian Lehner Reviewed-by: David Chase Auto-Submit: Keith Randall Reviewed-by: Keith Randall Reviewed-by: Ian Lance Taylor LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com

runtime: remove redundant fields from memory profile records

2026-03-28T20:07:33Z

The memProfCycle struct holds allocation counts and bytes allocated, and frees and bytes freed. But the memory profile records are already aggregated by allocation size, which is stored in the "size" field of the bucket struct. We can derive the bytes allocated/freed using the counts and the size we already store. Thus we can delete the bytes fields from memProfCycle, saving 64 bytes per memRecord. We can do something similar for the profilerecord.MemProfileRecord type. We just need to know the object size and we can derive the allocated and freed bytes accordingly. Change-Id: I103885c2f29471b25283e330674fc16d6a6a6964 Reviewed-on: https://go-review.googlesource.com/c/go/+/760140 LUCI-TryBot-Result: Go LUCI Reviewed-by: Dmitri Shuralyov Reviewed-by: Michael Pratt

runtime/pprof: fix missing Profile docs

2026-02-10T00:41:50Z

CL 688335 accidentally introduced a blank line between the Profile doc comment and the type definition, causing the entire doc to get dropped. Change-Id: I97b1c0e57d142d7caea6e543a0138ed6dcd1c3fe Reviewed-on: https://go-review.googlesource.com/c/go/+/743660 LUCI-TryBot-Result: Go LUCI Reviewed-by: Carlos Amedee Auto-Submit: Austin Clements

runtime: add GODEBUG=tracebacklabels=1 to include pprof labels in tracebacks

2025-11-25T04:07:56Z

Copy LabelSet to an internal package as label.Set, and include (escaped) labels within goroutine stack dumps. Labels are added to the goroutine header as quoted key:value pairs, so the line may get long if there are a lot of labels. To handle escaping, we add a printescaped function to the runtime and hook it up to the print function in the compiler with a new runtime.quoted type that's a sibling to runtime.hex. (in fact, we leverage some of the machinery from printhex to generate escape sequences). The escaping can be improved for printable runes outside basic ASCII (particularly for languages using non-latin stripts). Additionally, invalid UTF-8 can be improved. So we can experiment with the output format make this opt-in via a a new tracebacklabels GODEBUG var. Updates #23458 Updates #76349 Change-Id: I08e78a40c55839a809236fff593ef2090c13c036 Reviewed-on: https://go-review.googlesource.com/c/go/+/694119 LUCI-TryBot-Result: Go LUCI Reviewed-by: Michael Pratt Auto-Submit: Michael Pratt Reviewed-by: Alan Donovan

runtime/pprof: remove hard-coded sleep in CPU profile reader

2025-11-21T21:25:29Z

The CPU profiler reader goroutine has a hard-coded 100ms sleep between reads of the CPU profile sample buffer. This is done because waking up the CPU profile reader is not signal-safe on some platforms. As a consequence, stopping the profiler takes 200ms (one iteration to read the last samples and one to see the "eof"), and on many-core systems the reader does not wake up frequently enought to keep up with incoming data. This CL removes the sleep where it is safe to do so, following a suggestion by Austin Clements in the comments on CL 445375. We let the reader fully block, and wake up the reader when the buffer is over half-full. Fixes #63043 Updates #56029 Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest,gotip-linux-arm64-longtest,gotip-linux-386-longtest Change-Id: I9f7e7e9918a4a6f16e80f6aaf33103126568a81f Reviewed-on: https://go-review.googlesource.com/c/go/+/610815 LUCI-TryBot-Result: Go LUCI Reviewed-by: Michael Knyszek Reviewed-by: Mark Freeman

runtime,runtime/pprof: clean up goroutine leak profile writing

2025-11-12T16:08:34Z

Cleaned up goroutine leak profile extraction: - removed the acquisition of goroutineProfile semaphore - inlined the call to saveg when recording stacks instead of using doRecordGoroutineProfile, which had side-effects over goroutineProfile fields. Added regression tests for goroutine leak profiling frontend for binary and debug=1 profile formats. Added stress tests for concurrent goroutine and goroutine leak profile requests. Change-Id: I55c1bcef11e9a7fb7699b4c5a2353e594d3e7173 GitHub-Last-Rev: 5e9eb3b1d80c4d2d9b668a01f6b39a7b42f7bb45 GitHub-Pull-Request: golang/go#76045 Reviewed-on: https://go-review.googlesource.com/c/go/+/714580 Reviewed-by: Michael Pratt Reviewed-by: Michael Knyszek LUCI-TryBot-Result: Go LUCI Reviewed-by: Junyang Shao

runtime,net/http/pprof: goroutine leak detection by using the garbage collector

2025-10-02T18:06:21Z

Proposal #74609 Change-Id: I97a754b128aac1bc5b7b9ab607fcd5bb390058c8 GitHub-Last-Rev: 60f2a192badf415112246de8bc6c0084085314f6 GitHub-Pull-Request: golang/go#74622 Reviewed-on: https://go-review.googlesource.com/c/go/+/688335 LUCI-TryBot-Result: Go LUCI Reviewed-by: t hepudds Auto-Submit: Michael Knyszek Reviewed-by: Michael Knyszek Reviewed-by: Carlos Amedee

runtime/pprof: return errors from writing profiles

2025-05-13T17:01:48Z

Fixes #73107 Change-Id: I41f3e1bd1fdaca2f0e94151b2320bd569e258a51 Reviewed-on: https://go-review.googlesource.com/c/go/+/671576 Reviewed-by: Cherry Mui LUCI-TryBot-Result: Go LUCI Reviewed-by: Michael Pratt

runtime: remove GODEBUG=runtimecontentionstacks

2025-05-07T19:22:24Z

Go 1.22 promised to remove the setting in a future release once the semantics of runtime-internal lock contention matched that of sync.Mutex. That work is done, remove the setting. Previously reviewed as https://go.dev/cl/585639. For #66999 Change-Id: I9fe62558ba0ac12824874a0bb1b41efeb7c0853f Reviewed-on: https://go-review.googlesource.com/c/go/+/668995 LUCI-TryBot-Result: Go LUCI Reviewed-by: Michael Knyszek Auto-Submit: Rhys Hiltner Reviewed-by: Carlos Amedee

runtime/pprof: hide map runtime frames from heap profiles

2025-01-09T21:59:08Z

Heap profiles hide "runtime" frames like runtime.mapassign. This broke in 1.24 because the map implementation moved to internal/runtime/maps, and runtime/pprof only considered literal "runtime." when looking for runtime frames. It would be nice to use cmd/internal/objabi.PkgSpecial to find runtime packages, but that is hidden away in cmd. Fixes #71174. Change-Id: I6a6a636cb42aa17539e47da16854bd3fd8cb1bfe Reviewed-on: https://go-review.googlesource.com/c/go/+/641775 Auto-Submit: Michael Pratt LUCI-TryBot-Result: Go LUCI Reviewed-by: Michael Knyszek