I've now filed https://github.com/golang/go/issues/65328 to report this.
On Friday 3 March 2023 at 09:47:26 UTC Jochen Voss wrote: > Hi Peter, > > Thanks again for looking into this, and for your help! > > You mention that the blog post was long ago. I wonder whether the code to > write profile information is covered by the compatibility promise. If so, > probably the legacy WriteHeapProfile function could be made to implement > the required code to keep this working. Should a bug report be filed to > this effect? > > Similarly, should a bug report be filed about the mistake you found in the > pprof package documentation? > > All the best, > Jochen > On Thursday, 2 March 2023 at 15:36:24 UTC peterGo wrote: > >> On Thursday, March 2, 2023 at 2:03:22 AM UTC-5 Jochen Voss wrote: >> >> Hi Peter, >> >> Thanks a lot, giving the "-alloc_space" option makes all the difference! >> With this option, it also works for me. >> >> I wonder whether it meant to be the way that you have to give this >> option. Maybe something broke? In the blog entry >> https://go.dev/blog/pprof they didn't need this option to get the >> profile output. >> >> >> The Go blog post at https://go.dev/blog/pprof was written in 2011; it is >> now 2023. For up-to-date information, see the latest pprof package >> documentation at https://pkg.go.dev/runtime/pprof@latest. >> >> The pprof package documentation is incorrect: >> >> To add equivalent [go test] profiling support to a standalone program, >> add code like the following to your main function: >> >> // ... >> runtime.GC() // get up-to-date statistics >> if err := pprof.WriteHeapProfile(f); err != nil { >> log.Fatal("could not write memory profile: ", err) >> } >> // ... >> >> To obtain equivalent results, replace the above code with: >> >> // ... >> runtime.GC() // get up-to-date statistics >> if allocs := pprof.Lookup("allocs"); allocs == nil { >> log.Fatal("could not lookup memory profile: ") >> } else if err := allocs.WriteTo(f, 0); err != nil { >> >> log.Fatal("could not write memory profile: ", err) >> } >> // ... >> >> For your example, >> >> yyy.go: https://go.dev/play/p/epy4c3et1Io >> >> $ go build yyy.go && ./yyy >> $ go tool pprof mem.prof >> File: yyy >> Type: alloc_space >> Time: Mar 2, 2023 at 10:02am (EST) >> >> Entering interactive mode (type "help" for commands, "o" for options) >> (pprof) top >> Showing nodes accounting for 6975.42MB, 98.93% of 7050.77MB total >> Dropped 62 nodes (cum <= 35.25MB) >> >> Showing top 10 nodes out of 18 >> flat flat% sum% cum cum% >> 3564.88MB 50.56% 50.56% 3564.88MB 50.56% >> golang.org/x/exp/slices.Insert[.. >> <http://golang.org/x/exp/slices.Insert%5B..>.] (inline) >> 3122.14MB 44.28% 94.84% 3122.14MB 44.28% >> seehuhn.de/go/layout.(*Skip).Minus >> 117.01MB 1.66% 96.50% 117.01MB 1.66% >> seehuhn.de/go/layout.(*Skip).Clone (inline) >> 115.51MB 1.64% 98.14% 6919.54MB 98.14% >> seehuhn.de/go/layout.(*knuthPlassLineBreaker).Run >> 52.89MB 0.75% 98.89% 65.63MB 0.93% compress/flate.NewWriter >> 2.50MB 0.035% 98.92% 6926.54MB 98.24% >> seehuhn.de/go/layout.(*Engine).EndParagraph >> 0.50MB 0.0071% 98.93% 7050.27MB 100% main.main >> 0 0% 98.93% 65.63MB 0.93% compress/flate.NewWriterDict >> 0 0% 98.93% 65.63MB 0.93% compress/zlib.(*Writer).Write >> 0 0% 98.93% 65.63MB 0.93% >> compress/zlib.(*Writer).writeHeader >> (pprof) quit >> $ >> >> Peter >> >> -- 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/52a65cdb-afee-4101-9602-42c0d17a3088n%40googlegroups.com.
