[go-nuts] Re: go analysis memory mallocs

package main import "runtime" func main() { m := new(runtime.MemStats) runtime.ReadMemStats(m) cap := 1024 println("debug0") s := make([]byte, cap) println("debug1") _ = s runtime.ReadMemStats(m) println("memstats:", m.Alloc, m.Mallocs) } I use go1.4.2 and In

[go-nuts] Re: go analysis memory mallocs

e, "kind=", typ.kind, "needzero=", needzero) 在 2016年9月29日星期四 UTC+8下午9:04:58，Dave Cheney写道： > > You should use Go 1.7.1 or later. > > On Thursday, 29 September 2016 23:00:25 UTC+10, 刘桂祥 wrote: >> >> package main >> >> import "runtime&quo

Re: [go-nuts] Re: go escape analysis

ich means the make operation escapes its scope and > subsequently, is heap allocated. If you want more information about why > something escapes, try compiling with -gcflags "-m -m" for an explanation > of the escape analysis information. > > On Wed, Sep 28, 2016 at 7:

Re: [go-nuts] go closure escape analysis

to escape to the heap. > > On Wed, Oct 5, 2016 at 4:46 PM, 刘桂祥 <liuguix...@gmail.com > > wrote: > >> 1: In example2_modified.go (y=x line should be *y=x ?) and that is the >> same as example1.go ??? >>but in example1.go y is escapted and example2.go

Re: [go-nuts] go closure escape analysis

sformed into something like > > // example2_modified.go > > package main > > func main() { > var y int > func(y *int, x int) { > y = x > }(, 42) > } > > and then the same analysis from above is applied. y should not escape to > the heap here, similar to exam

[go-nuts] golang memory allocation

package main import ( "fmt" _ "net/http/pprof" "testing" ) // 8 Bytes/op 1 allocs/op func BenchmarkFmt1(b *testing.B) { b.ReportAllocs() for i := 0; i < b.N; i++ { fmt.Println(100) } } // 16 Bytes/op 1 allocs/op func BenchmarkFmt2(b *testing.B) {

Re: [go-nuts] go closure escape analysis

ing/closing over a non-pointer value would cause it to escape. > > It's a bit confusing, but to restate, in example1, y should not escape > even though it currently does. > > On Mon, Oct 3, 2016 at 11:09 PM, 刘桂祥 <liuguix...@gmail.com > > wrote: > >> // example1.go >

[go-nuts] when the runtime decide to threadcreate

package main import ( "bufio" "net/http" _ "net/http/pprof" "os" "time" ) func main() { go func() { http.ListenAndServe(":8080", nil) }() reader := bufio.NewReader(os.Stdin) for i := 0; i < 100; i++ { go func(id int) { for {

[go-nuts] go analysis memory mallocs

// example1.go package main import "runtime" func main() { m := new(runtime.MemStats) runtime.ReadMemStats(m) println(m.Alloc, m.Mallocs) cap := 1024 * 1024 * 3 s := make([]byte, cap) _ = s runtime.ReadMemStats(m) println(m.Alloc, m.Mallocs) } go run

[go-nuts] Re: go analysis memory mallocs

package main import "runtime" func init() { runtime.MemProfileRate = 1 } func main() { m := new(runtime.MemStats) runtime.ReadMemStats(m) println(m.Alloc, m.Mallocs) cap := 1024 * 1024 * 4 s := make([]byte, cap) _ = s runtime.ReadMemStats(m) println(m.Alloc,

[go-nuts] Re: go analysis memory mallocs

package main import "runtime" func init() { runtime.MemProfileRate = 1 } func main() { m := new(runtime.MemStats) runtime.ReadMemStats(m) println(m.Alloc, m.Mallocs) cap := 1024 * 1024 * 4 s := make([]byte, cap) _ = s runtime.ReadMemStats(m) println(m.Alloc,

[go-nuts] Re: go compile for memory allocation

https://github.com/golang/go/issues/17275 在 2016年9月29日星期四 UTC+8下午2:57:08，Dave Cheney写道： > > Don't forget to log that issue. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send

[go-nuts] Re: go analysis memory mallocs

In my two examples, I use variable in makeslice that it will all escape to the heap , But I just want to use runtime.ReadMemStats to lookup it and find strange

Re: [go-nuts] Re: go escape analysis

the scope > of the for statement, which means the make operation escapes its scope and > subsequently, is heap allocated. If you want more information about why > something escapes, try compiling with -gcflags "-m -m" for an explanation > of the escape analysis information. > > On Wed,

[go-nuts] go compile for memory allocation

// example1.go packge main func main() { s := make([]byte, 1024, 1024) _ = s } s will be allocated in stack and lookup assembl e code

[go-nuts] go escape analysis

// example1.go package main func main() { for i := 0; i < 2; i++ { m := make(map[int]int) m[1] = 100 } } main

[go-nuts] about interface data pointer

package main import ( "fmt" ) func main() { a := interface{}(100) println(, a) fmt.Sprint(a) } go run x.go the output: 0xc42003bf18 (0x89040,0xc42000a2c0) I just want to ask 0xc42000a2c0 as the a (interface{}) 's data pointer is point to where ? heap ? also I test this:

Re: [go-nuts] Re: go escape analysis

>> analysis. >> If you are convinced that something doesn't escape and that the compiler >> should be able to figure it out, you can try filing an issue about that >> with the code and output of -gcflags=-m. >> >> > On Fri, Sep 30, 2016 at 5:20 AM,

[go-nuts] Re: go escape analysis

go 1.7 在 2016年9月28日星期三 UTC+8下午10:41:09，Dave Cheney写道： > > Which version of Go? > > On Thursday, 29 September 2016 00:18:29 UTC+10, 刘桂祥 wrote: >> >> // example1.go >> package main >> >> >> func main() { >> >>

[go-nuts] golang too many json unmarshal trigger gc frequency to many

In my server many requests need to handle a loop to unmarshal json strings and I find gc is very frequency -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an

Re: [go-nuts] Multiple-reader single-writer map access is safe ?

Taylor写道： > > On Thu, Nov 3, 2016 at 11:30 PM, 刘桂祥 <liuguix...@gmail.com > > wrote: > > > >very thanks , I am unfamiliar with the cpu out-of-order execution , > but > > I doubt if my three line code is related ,it will reorder it ?? > > I want to

Re: [go-nuts] golang closure variable

0091 (main.go:11) PCDATA $0, $1 0x005b 00091 (main.go:11) CALL time.Sleep(SB) 0x0060 00096 (main.go:12) MOVQ 48(SP), BP 0x0065 00101 (main.go:12) ADDQ $56, SP 0x0069 00105 (main.go:12) RET 0x006a 00106 (main.go:12) NOP 0x006a 00106 (main.go:5) CALL runtime.morestack_noctxt(SB) 0x006f 00111

Re: [go-nuts] golang closure variable

7 00231 (main.go:5) CALL runtime.morestack_noctxt(SB) 0x00ec 00236 (main.go:5) JMP 0 在 2016年11月3日星期四 UTC+8下午2:56:10，Ian Lance Taylor写道： > > On Wed, Nov 2, 2016 at 11:48 PM, 刘桂祥 <liuguix...@gmail.com > > wrote: > > I just want to look what variable datastructure is passe

[go-nuts] golang closure variable

In golang closure func ,the needed outer variable is passed by reference but when the variable self is a reference in example.go , the closure func

[go-nuts] Multiple-reader single-writer map access is safe ?

// example.go package main var gMap = make(map[int]int) func w() { temp := make(map[int]int) temp[1] = 100 temp[2] = 200 gMap = temp// Does the compiler or cpu will reorder temp[1]=100, temp[2]=200, gMap=temp ?? } func r() { local := gMap println(local[1],

Re: [go-nuts] Multiple-reader single-writer map access is safe ?

In my write goroutine I don't modify the map key (data structure) but set the variable point to another map address ,this is a pointer assignment and is atomic 在 2016年11月4日星期五 UTC+8下午1:22:20，Ian Lance Taylor写道： > > On Thu, Nov 3, 2016 at 10:19 PM, 刘桂祥 <liuguix...@gmail.com &

Re: [go-nuts] Multiple-reader single-writer map access - is this lockless workaround safe?

sorry could you provide a complete example ? I try this but not find question package main import "time" type T struct{ x int } var global *T func f() { p := new(T) p.x = 1 global = p // "publish" the new T (racy!) } func g() { p := global if p != nil { // println(p.x) // may

Re: [go-nuts] Multiple-reader single-writer map access is safe ?

can you explain why whis ? 在 2016年11月4日星期五 UTC+8下午1:16:39，Ian Lance Taylor写道： > > On Thu, Nov 3, 2016 at 8:37 PM, 刘桂祥 <liuguix...@gmail.com > > wrote: > > // example.go > > > > package main > > > > var gMap = make(map[int]int) > >

Re: [go-nuts] Multiple-reader single-writer map access is safe ?

very thanks , I am unfamiliar with the cpu *out-of-order execution , but I doubt if my three line code is related ,it will reorder it ??* 在 2016年11月4日星期五 UTC+8下午1:38:12，Ian Lance Taylor写道： > > On Thu, Nov 3, 2016 at 10:28 PM, 刘桂祥 <liuguix...@gmail.com > > wrote: > &

[go-nuts] Re: golang cpu usage question

e. Assist mode causes goroutines to > "pay" for their allocation by doing some mark and sweep work each time they > allocate. > > The execution trace can show this more clearly. > > On Tuesday, 28 March 2017 17:59:19 UTC+11, 刘桂祥 wrote: >> >> my production p

[go-nuts] Re: golang cpu usage question

my production program data: ... gc 149 @91.330s 6%: 6.8+557+0.50+1.0+10 ms clock, 20+557+0+1841/0/1304+31 ms cpu, 3694->3793->2016 MB, 3789 MB goal, 48 P gc 150 @92.012s 6%: 2.9+505+0.32+0.58+9.5 ms clock, 11+505+0+1756/0.014/1574+38 ms cpu, 3739->3805->1987 MB, 3835 MB goal, 48 P gc 151

[go-nuts] Re: golang cpu usage question

Hi Dave: very thanks your timely response two more question 1. GODEBUG=gctrace=1 Do have some method get these quota from runtime package apis ? 2. In go1.7 the concurent gc could occupy all cpu core ?? does it have cpu usgae limit ? 在

[go-nuts] golang cpu usage question

As we know go have optimise its gc stw-pause-time ,but it has some trade-off ; it implements concurent gc and will grab cpu resources with your application In some high CPU usage application, there are long time request case caused by gc I want to know How to monitor my application in CPU

[go-nuts] golang precise gc

package main import ( "fmt" "runtime" "unsafe" ) func main() { var m runtime.MemStats runtime.ReadMemStats() println(m.HeapObjects, m.Mallocs) runtime.GC() runtime.ReadMemStats() println(m.HeapObjects, m.Mallocs) runtime.GC() runtime.ReadMemStats() println(m.HeapObjects, m.Mallocs) p :=

[go-nuts] Re: golang cpu usage question

now In my application 48 core set GODEBUG=gctrace=1 the gc CPU percent is 17% but my server request have many long time case want to know the CPU percent in witch percentage is hight?? 在 2017年3月27日星期一 UTC+8下午6:55:47，Dave Cheney写道： > > > > On Monday, 27 March 2017 21:12:44 UTC+1

[go-nuts] Re: golang cpu usage question

package main import ( "fmt" "time" ) func foo() { str := "" for i := 0; i < 1000; i++ { str += "aa" } } func main() { for i := 0; i < 200; i++ { go func() { for {

Re: [go-nuts] go build -gcflags '-N -l' don't work

Taylor写道： > > On Thu, Apr 13, 2017 at 10:45 PM, 刘桂祥 <liuguix...@gmail.com > > wrote: > > go1.7.1 > > > > go run -gcflags '-N -l -m' example.go > > It is the -m flag that is generating the output you see. > > If there is some other bug, please let us

[go-nuts] Re: Large GC pauses with large map

try use value type example: map[string]*struct => map[[20]byte]struct 在 2017年4月20日星期四 UTC+8下午9:49:49，Lee Armstrong写道： > > See attached graph which shows the GC pauses of an application we have. > > I am frequently seeing pauses of 1-1.5 seconds. This is using Go 1.8.1 and > have a large map

[go-nuts] go build -gcflags '-N -l' don't work

// example.go package main import "runtime" type S struct{} func main() { var stats runtime.MemStats runtime.ReadMemStats() println(stats.Mallocs) var x S runtime.ReadMemStats() println(stats.Mallocs) _ = *ref(x) runtime.ReadMemStats() println(stats.Mallocs) } func ref(z S) *S {

Re: [go-nuts] go build -gcflags '-N -l' don't work

go1.7.1 go run -gcflags '-N -l -m' example.go 在 2017年4月14日星期五 UTC+8下午1:18:26，Ian Lance Taylor写道： > > On Thu, Apr 13, 2017 at 8:33 PM, 刘桂祥 <liuguix...@gmail.com > > wrote: > > // example.go > > package main > > > > > > import "runtime"

Re: [go-nuts] go build -gcflags '-N -l' don't work

gt; # command-line-arguments > ./example.go:27:9: escapes to heap > ./example.go:26:16: moved to heap: z > ./example.go:14:23: main does not escape > ./example.go:17:23: main does not escape > ./example.go:20:23: main does not escape > 83 > 83 > 84 > 1 > $ > &g

Re: [go-nuts] golang thrift server 28k/s request client many dial tcp timeout ,why??

client: dial tcp 100.70.186.38:9783: i/o timeout when I modify the server /proc/sys/net/core/netdev_max_backlog16384 /proc/sys/net/core/somaxconn 16384 the client dial timeout decrease some percent 在 2017年6月9日星期五 UTC+8上午12:10:15，Shawn Milochik写道： > > What error are you

[go-nuts] golang thrift server 28k/s request client many dial tcp timeout ,why??

I have a very simple golang thrift server. the handle is very easy just to return But when I use another machine to benchmark the server ,when the qps to 28K/s , client have many dial tcp io/timeout I don't konw the reason ? is the client or server's problem? -- You

Re: [go-nuts] golang thrift server 28k/s request client many dial tcp timeout ,why??

I just want to bench the simple server accept new connection now I create a new simple tcp server and use tcp short connection to bench it the result is also that client have many dial i/o timeout does it is client's question ?? 在 2017年6月9日星期五 UTC+8下午9:28:55，Shawn

[go-nuts] Re: dial io timeout and tcp short connection performance bottleneck

check output of netstat to confirm that. > > On Sunday, June 11, 2017 at 9:48:30 AM UTC+8, 刘桂祥 wrote: >> >> //question >> > I write a simple golang tcp server >> > and use tcp short connect client to bench it. >> > when qps up to 28K, cli

[go-nuts] dial io timeout and tcp short connection performance bottleneck

> I write a simple tcp server with golang > and use tcp short connect client to bench it. > when qps to 28K, client have many dial io timeout > > I don't know what is the performance bottleneck?? > > I modify the server: > cat

[go-nuts] Re: dial io timeout and tcp short connection performance bottleneck

HI Matthew: Because I don't konw the performance bottleneck; do you mean the tcp syn queue (half open queue) is full ??but I don't see the syn flood warn message in /var/log/messages 在 2017年6月11日星期日 UTC+8下午7:03:58，Matthew Stevenson写道： > > Are you exhausting the local TCP sockets?

Re: [go-nuts] golang thrift server 28k/s request client many dial tcp timeout ,why??

ry time you have a request, you pay the session setup > time on every request. You could maybe look into batch-framing some of them > which will improve the TCP window and likely increase throughput. > > On Sat, Jun 10, 2017 at 11:51 AM 刘桂祥 <liuguix...@gmail.com > > wrote:

[go-nuts] dial io timeout and tcp short connection performance bottleneck

//question > I write a simple golang tcp server > and use tcp short connect client to bench it. > when qps up to 28K, client have many dial i/o timeout > > I don't know what is the performance bottleneck?? > > I modify the server: > cat

Re: [go-nuts] golang preempt schedule how work ?

Thanks a lot! 在 2017年9月8日星期五 UTC+8下午8:23:39，Ian Lance Taylor写道： > > On Mon, Sep 4, 2017 at 10:02 PM, 刘桂祥 <liuguix...@gmail.com > > wrote: > > > > I have a question about golang preempt schedule, here is my example > code; > > > > I doubt why the

[go-nuts] golang preempt schedule how work ?

I have a question about golang preempt schedule, here is my example code; I doubt why the bar groutine don't happen preempt schedule? (I build with -gcflags “-N -l” to stop func inline) More if my server with one or two cpu bound worker goroutine runing, when the gc need stop the world,

Re: [go-nuts] golang gc stop the world how to stop cpu busy goroutine?

But I build with -gcflags "-N -l" here is gdb code: (gdb) Dump of assembler code for function main.main: 0x2100 <+0>: mov%gs:0x8a0,%rcx 0x2109 <+9>: cmp0x10(%rcx),%rsp 0x210d <+13>: jbe0x216c 0x210f <+15>:

[go-nuts] golang gc stop the world how to stop cpu busy goroutine?

when have one or two cpu busy goroutine in my server (example for loop empty), the gc stop the world how to stop the goroutine ? -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it,

Re: [go-nuts] golang gc stop the world how to stop cpu busy goroutine?

Yes, I just want to let the bar func goroutine run first or replace runtime.Gosched() with time.Sleep, But I still doubt why add1 in bar func don't happen preempt schedule ? 在 2017年9月4日星期一 UTC+8下午3:25:04，John Souvestre写道： > > I think that you put the call to runtime.Gosched() in the wrong

[go-nuts] Re: about golang escape analysis

very very thanks! cannot inline copyIface1: has ... args from *a[0].(string) (indirection) key escapes to heap 在 2017年12月3日星期日 UTC+8下午4:08:41，Dave Cheney写道： > > Add -gcflags=“-m -m” will tell you. -- You received this message because you are subscribed to the Google Groups "golang-nuts"

[go-nuts] about golang escape analysis

package main import "testing" var gbuf []byte var gi int func BenchmarkCopy1(b *testing.B) { b.ReportAllocs() for i := 0; i < b.N; i++ { m := make(map[string]int, 5) for i := 0; i < 5; i++ { m["100"] = i } for key := range m { copyIface1(key, key) } } } func BenchmarkCopy2(b *testing.B) {

[go-nuts] golang gc time STW1=>Mark=>STW2

package main import ( "runtime" _ "net/http/pprof" "net/http" "time" ) var ch = make(chan struct{},1) func printMem() { var mem runtime.MemStats runtime.ReadMemStats() println(mem.HeapObjects) } func easy() { <-ch } func bussy() { sum := 0 for

[go-nuts] Re: golang gc time STW1=>Mark=>STW2

195+0.26+0.025 ms 0.065+0.82+0.041 ms 242+0.32+0.016 ms 0.010+0.37+0.039 ms 233+0.33+0.014 ms version go1.9.2 I want to ask why the third phrase mark-termination time is always short, it also need STW ?? 在 2017年12月27日星期三 UTC+8下午5:14:52，Dave Cheney写道： > > I’m sorry I don’t understand the