delta/go-git.git/src/runtime/debug.go, branch dev.boringcrypto

all: gofmt main repo

2022-04-11T16:34:30+00:00

[This CL is part of a sequence implementing the proposal #51082.
The design doc is at https://go.dev/s/godocfmt-design.]

Run the updated gofmt, which reformats doc comments,
on the main repository. Vendored files are excluded.

For #51082.

Change-Id: I7332f099b60f716295fb34719c98c04eb1a85407
Reviewed-on: https://go-review.googlesource.com/c/go/+/384268
Reviewed-by: Jonathan Amsterdam 
Reviewed-by: Ian Lance Taylor

runtime: add a maymorestack hook that moves the stack

2021-11-05T00:52:09+00:00

This adds a maymorestack hook that moves the stack at every
cooperative preemption point.

For #48297.

Change-Id: Ic15f9bcbc163345e6422586302d57fda4744caec
Reviewed-on: https://go-review.googlesource.com/c/go/+/359797
Trust: Austin Clements 
Run-TryBot: Austin Clements 
TryBot-Result: Go Bot 
Reviewed-by: Cherry Mui 
Reviewed-by: Michael Pratt 
Reviewed-by: David Chase

runtime: add always-preempt maymorestack hook

2021-11-05T00:52:08+00:00

This adds a maymorestack hook that forces a preemption at every
possible cooperative preemption point. This would have helped us catch
several recent preemption-related bugs earlier, including #47302,
 #47304, and #47441.

For #48297.

Change-Id: Ib82c973589c8a7223900e1842913b8591938fb9f
Reviewed-on: https://go-review.googlesource.com/c/go/+/359796
Trust: Austin Clements 
Run-TryBot: Austin Clements 
TryBot-Result: Go Bot 
Reviewed-by: Cherry Mui 
Reviewed-by: Michael Pratt 
Reviewed-by: David Chase

runtime: make ncgocall a global counter

2021-06-25T17:31:39+00:00

ncgocall was stored per M, runtime.NumCgoCall lost the counter when a M die.

Fixes #46789

Change-Id: I85831fbb2713f4c30d1800d07e1f47aa0031970e
GitHub-Last-Rev: cbc15fa870de776d3fbf3b62fc9a5e01792e6a26
GitHub-Pull-Request: golang/go#46842
Reviewed-on: https://go-review.googlesource.com/c/go/+/329729
Run-TryBot: Ian Lance Taylor 
TryBot-Result: Go Bot 
Reviewed-by: Ian Lance Taylor 
Trust: Alexander Rakoczy

runtime: update docs for GOMAXPROCS

2020-09-10T14:44:25+00:00

https://github.com/golang/go/blob/master/doc/effective_go.html#L3211 is used to update the docs comment for `GOMAXPROCS` function.

Fixes #41275

Change-Id: I39f58e93a267c6e9f3ac6638ed51acbe5284ada2
GitHub-Last-Rev: e45c8ac5873979397d747838fd8d41e252aec489
GitHub-Pull-Request: golang/go#41276
Reviewed-on: https://go-review.googlesource.com/c/go/+/253537
Reviewed-by: Keith Randall

runtime: don't hold worldsema across mark phase

2020-03-18T19:13:50+00:00

This change makes it so that worldsema isn't held across the mark phase.
This means that various operations like ReadMemStats may now stop the
world during the mark phase, reducing latency on such operations.

Only three such operations are still no longer allowed to occur during
marking: GOMAXPROCS, StartTrace, and StopTrace.

For the former it's because any change to GOMAXPROCS impacts GC mark
background worker scheduling and the details there are tricky.

For the latter two it's because tracing needs to observe consistent GC
start and GC end events, and if StartTrace or StopTrace may stop the
world during marking, then it's possible for it to see a GC end event
without a start or GC start event without an end, respectively.

To ensure that GOMAXPROCS and StartTrace/StopTrace cannot proceed until
marking is complete, the runtime now holds a new semaphore, gcsema,
across the mark phase just like it used to with worldsema.

This change is being landed once more after being reverted in the Go
1.14 release cycle, since CL 215157 allows it to have a positive
effect on system performance.

For the benchmark BenchmarkReadMemStatsLatency in the runtime, which
measures ReadMemStats latencies while the GC is exercised, the tail of
these latencies reduced dramatically on an 8-core machine:

name                   old 50%tile-ns  new 50%tile-ns  delta
ReadMemStatsLatency-8      4.40M ±74%      0.12M ± 2%  -97.35%  (p=0.008 n=5+5)

name                   old 90%tile-ns  new 90%tile-ns  delta
ReadMemStatsLatency-8       102M ± 6%         0M ±14%  -99.79%  (p=0.008 n=5+5)

name                   old 99%tile-ns  new 99%tile-ns  delta
ReadMemStatsLatency-8       147M ±18%         4M ±57%  -97.43%  (p=0.008 n=5+5)

Fixes #19812.

Change-Id: If66c3c97d171524ae29f0e7af4bd33509d9fd0bb
Reviewed-on: https://go-review.googlesource.com/c/go/+/216557
Run-TryBot: Michael Knyszek 
TryBot-Result: Gobot Gobot 
Reviewed-by: Cherry Zhang

Revert "runtime: don't hold worldsema across mark phase"

2020-01-24T23:27:33+00:00

This reverts commit 7b294cdd8df0a9523010f6ffc80c59e64578f34b, CL 182657.

Reason for revert: This change may be causing latency problems
for applications which call ReadMemStats, because it may cause
all goroutines to stop until the GC completes.

https://golang.org/cl/215157 fixes this problem, but it's too
late in the cycle to land that.

Updates #19812.

Change-Id: Iaa26f4dec9b06b9db2a771a44e45f58d0aa8f26d
Reviewed-on: https://go-review.googlesource.com/c/go/+/216358
Run-TryBot: Michael Knyszek 
TryBot-Result: Gobot Gobot 
Reviewed-by: Cherry Zhang

runtime: don't hold worldsema across mark phase

2019-09-04T15:53:59+00:00

This change makes it so that worldsema isn't held across the mark phase.
This means that various operations like ReadMemStats may now stop the
world during the mark phase, reducing latency on such operations.

Only three such operations are still no longer allowed to occur during
marking: GOMAXPROCS, StartTrace, and StopTrace.

For the former it's because any change to GOMAXPROCS impacts GC mark
background worker scheduling and the details there are tricky.

For the latter two it's because tracing needs to observe consistent GC
start and GC end events, and if StartTrace or StopTrace may stop the
world during marking, then it's possible for it to see a GC end event
without a start or GC start event without an end, respectively.

To ensure that GOMAXPROCS and StartTrace/StopTrace cannot proceed until
marking is complete, the runtime now holds a new semaphore, gcsema,
across the mark phase just like it used to with worldsema.

Fixes #19812.

Change-Id: I15d43ed184f711b3d104e8f267fb86e335f86bf9
Reviewed-on: https://go-review.googlesource.com/c/go/+/182657
Run-TryBot: Michael Knyszek 
TryBot-Result: Gobot Gobot 
Reviewed-by: Keith Randall 
Reviewed-by: Cherry Zhang

cmd/go: move runtime/debug.modinfo to runtime.modinfo

2019-04-23T14:21:30+00:00

It is easier to ensure that the symbol is always present
if we move it to package runtime. Avoids init-time work.
Also moves it next to buildVersion, the other similar symbol.

Setting up for "go version ".

For #31624.

Change-Id: I943724469ce6992153e701257eb6f12da88c8e4e
Reviewed-on: https://go-review.googlesource.com/c/go/+/173341
Run-TryBot: Russ Cox 
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick

runtime: add js/wasm architecture

2018-05-08T00:17:34+00:00

This commit adds the js/wasm architecture to the runtime package.
Currently WebAssembly has no support for threads yet, see
https://github.com/WebAssembly/design/issues/1073. Because of that,
there is no preemption of goroutines and no sysmon goroutine.

Design doc: https://docs.google.com/document/d/131vjr4DH6JFnb-blm_uRdaC0_Nv3OUwjEY5qVCxCup4
About WebAssembly assembly files: https://docs.google.com/document/d/1GRmy3rA4DiYtBlX-I1Jr_iHykbX8EixC3Mq0TCYqbKc

Updates #18892

Change-Id: I7f12d21b5180500d55ae9fd2f7e926a1731db391
Reviewed-on: https://go-review.googlesource.com/103877
Run-TryBot: Brad Fitzpatrick 
TryBot-Result: Gobot Gobot 
Reviewed-by: Austin Clements