Thanks, Kurtis, The production version of this code runs as a regular web server. I was profiling in CGI just to simplify the configuration.
Regards, Steve On Wed, Jan 12, 2022 at 5:34 PM Kurtis Rader <kra...@skepticism.us> wrote: > FWIW, I had the same suspicion as Robert. In my experience a CGI task that > takes less than, say, 200ms is going to be swamped by startup costs. It's > usually better to use the FastCGI protocol > <https://en.wikipedia.org/wiki/FastCGI#:~:text=FastCGI%20is%20a%20binary%20protocol,programs%20with%20a%20web%20server.&text=FastCGI's%20main%20aim%20is%20to,requests%20per%20unit%20of%20time.> > in that situation. > > On Wed, Jan 12, 2022 at 4:41 PM Steve Roth <st...@rothskeller.net> wrote: > >> Hi, Robert, >> >> The request *should* be super short, but it was actually taking 2.5 >> seconds. That was the whole reason I started trying to profile it, to >> figure out why a simple request was taking so long. >> >> Ian's suggestion of heap tracing found the issue for me: there was an >> unexpected allocation of a 13MB block in there. Tracing that, I found the >> root cause, which was corrupted data in my site database. Many thanks to >> all for the help. >> >> Regards, >> Steve >> >> >> On Wed, Jan 12, 2022 at 4:20 PM robert engels <reng...@ix.netcom.com> >> wrote: >> >>> Are you certain that the requests aren’t super short - so all you are >>> measuring is the runtime startup time / and the overhead of parsing the CGI >>> “protocol". This is not insignificant. CGI really only works well for long >>> requests IMO. >>> >>> On Jan 12, 2022, at 5:29 PM, Steve Roth <st...@rothskeller.net> wrote: >>> >>> Thank you, Ian. From the function names, I suspected that the 70% chain >>> was the garbage collector. But in this run, garbage collection was turned >>> off with GOGC=off, and that was verified with GODEBUG=gctrace=1. So I >>> thought perhaps they must be something else. >>> >>> I will proceed with heap profiling as you suggest. (And of course I've >>> reviewed pprof blog post many times.) >>> >>> Regards, >>> Steve >>> >>> >>> On Wed, Jan 12, 2022 at 2:58 PM Ian Lance Taylor <i...@golang.org> >>> wrote: >>> >>>> On Wed, Jan 12, 2022 at 1:54 PM Steve Roth <st...@rothskeller.net> >>>> wrote: >>>> > >>>> > I am attempting to profile my code, and I'm unable to interpret the >>>> results. So first, the meta-question is, what's the best forum to use to >>>> request help with such things? >>>> >>>> This is a good place. See also https://golang.org/wiki/Questions. >>>> >>>> >>>> > The chain that is taking 70% of the time is >>>> > >>>> > gcBgMarkWorker >>>> > >>>> > systemstack >>>> > >>>> > gcBgMarkWorker.func2 >>>> > >>>> > gcDrain >>>> > >>>> > markroot >>>> > >>>> > markroot.func1 >>>> > >>>> > suspendG >>>> >>>> This is the concurrent garbage collector. >>>> >>>> >>>> > The chain that is taking 17% of the time is >>>> > >>>> > mcall >>>> > >>>> > park_m >>>> > >>>> > schedule >>>> > >>>> > findrunnable >>>> > >>>> > stopm >>>> > >>>> > mPark >>>> > >>>> > notesleep >>>> > >>>> > futexsleep >>>> > >>>> > futex >>>> > >>>> > Again I have no clue what this is doing. Any guidance is welcome, >>>> including pointers to other forums better suited for such questions. >>>> >>>> This is the goroutine scheduler. >>>> >>>> If your program is CPU bound (as it should be based on your >>>> description) then 70% in the garbage collector is a lot. The next >>>> step is to collect a heap profile to see where the memory is being >>>> allocated. You may want to look at https://go.dev/blog/pprof, old but >>>> still valid. >>>> >>>> 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/CAAnpqKGzr4MNfnC4Tqam2NoOt9AJ4NKP_Hiarv5usaYQYG1iNw%40mail.gmail.com >>> <https://groups.google.com/d/msgid/golang-nuts/CAAnpqKGzr4MNfnC4Tqam2NoOt9AJ4NKP_Hiarv5usaYQYG1iNw%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >>> >>> -- >> 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/CAAnpqKEG8Brwe1yHLdWzSX76rCCidybTR-PC4HBgWVKEi7CE7A%40mail.gmail.com >> <https://groups.google.com/d/msgid/golang-nuts/CAAnpqKEG8Brwe1yHLdWzSX76rCCidybTR-PC4HBgWVKEi7CE7A%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > Kurtis Rader > Caretaker of the exceptional canines Junior and Hank > -- 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/CAAnpqKHoxedxjWN8rOUsF6-Nd3gSHSeFKnnaPbwskR4gAxY-gQ%40mail.gmail.com.
