On Sun, Oct 20, 2019 at 12:23 AM Nidhi Agrawal <nidhi11...@gmail.com> wrote: > > Ok, Is it necessary to call SetBlockProfileRate at the start of application? > If not then we can call it just before starting block profile and after block > profile interval (eg. 30 seconds) when profiling finishes then we can reset > it to 0.
As far as I know you can call SetBlockProfileRate at any time. Why do you think that it must be called at the start of the application? Ian > On Sun, Oct 20, 2019 at 12:48 PM Ian Lance Taylor <i...@golang.org> wrote: >> >> On Sat, Oct 19, 2019 at 10:17 PM Nidhi Agrawal <nidhi11...@gmail.com> wrote: >> > >> > >> > https://golang.org/src/runtime/mprof.go, >> > https://golang.org/pkg/net/http/pprof/ here it is mentioned that we need >> > to set SetBlockProfileRate to get enable block profile. >> > >> > In case of block profiling if I set rate just before profiling and reset >> > it to 0 after profiling i am not getting any data. >> > >> > I am doing something like: >> > SetBlockProfileRate(1) >> > pprof.Lookup("block").WriteTo(f, 0); >> > SetBlockProfileRate(0) >> >> If that is exactly what you are doing, then that doesn't work for CPU >> profiling either. You need to call SetBlockProfileRate, then do some >> work, then fetch the profile. >> >> Ian >> >> >> > On Sun, Oct 20, 2019 at 10:24 AM Ian Lance Taylor <i...@golang.org> wrote: >> >> >> >> On Sat, Oct 19, 2019 at 7:34 PM Nidhi Agrawal <nidhi11...@gmail.com> >> >> wrote: >> >> > >> >> > We don't need to set MemProfileRate. It is about block and mutex >> >> > profiling where we need to set the rate (SetBlockProfileRate, >> >> > SetMutexProfileFraction) at application start. Is there any performance >> >> > impacts of doing that ? >> >> > >> >> > It is not causing any issue we want to enable block and mutex profiling >> >> > so i am thinking if we can do something like >> >> > SetBlockProfileRate(1) >> >> > pprof.Lookup("block").WriteTo(f, 0); >> >> > sleep(20) >> >> > SetBlockProfileRate(0) >> >> > just like how cpu and trace profile works. But i am curious why isn't >> >> > it not already done in the library. What can be the reason behind this? >> >> > >> >> > I am curious why they are different from cpu and trace profiling, >> >> > trying to understand the inner working of this. It would be really >> >> > helpful if you can give me some pointers on where i can read about the >> >> > high level design of the pprof. >> >> >> >> Oh, sorry, I misread what you were asking. But now I'm not sure what >> >> you are asking. You said >> >> >> >> > On the other hand for mutex and block profiling, it expects us to set >> >> > the rate at the start of the application and while calling profiling, >> >> > it just gathers the information and return. >> >> >> >> That's how memory profiling works. You don't have to set the mutex >> >> and profiling rates at the start of the application. You can set them >> >> when you want to start profiling, as you suggest. Is there some >> >> documentation that says otherwise? >> >> >> >> Sorry, I don't know of any documentation describing the profiling >> >> implementation. >> >> >> >> Ian -- 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 email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAOyqgcUpViwb0zzCR%3DBRWJ-GpqYdiaOeGCwHY_McODyEUcCvAQ%40mail.gmail.com.
