What is runtime.gopark?

[Tamás Gulácsi]

Hi,

I have a strange pprof of a camlistored process which eats 160% from my 2 cores, constantly:

gthomas@tequila:~$ go tool pprof -cum ~/src/camlistore.org/bin/camlistored http://localhost:3179/debug/pprof/goroutine                                                   

Fetching profile from http://localhost:3179/debug/pprof/goroutine

Saved profile in /home/gthomas/pprof/pprof.camlistored.localhost:3179.goroutine.001.pb.gz

Entering interactive mode (type "help" for commands)

(pprof) top20

49 of 51 total (96.08%)

Showing top 20 nodes out of 66 (cum >= 1)

      flat  flat%   sum%        cum   cum%

         1  1.96%  1.96%         51   100%  runtime.goexit

        46 90.20% 92.16%         46 90.20%  runtime.gopark

         0     0% 92.16%         21 41.18%  runtime.goparkunlock

         0     0% 92.16%         21 41.18%  runtime.selectgo

         0     0% 92.16%         21 41.18%  runtime.selectgoImpl

         0     0% 92.16%         17 33.33%  runtime.chanrecv

         0     0% 92.16%         14 27.45%  runtime.chanrecv1

         0     0% 92.16%         13 25.49%  camlistore.org/pkg/context.(*Context).New.func1

         0     0% 92.16%          3  5.88%  camlistore.org/third_party/github.com/syndtr/goleveldb/leveldb.(*DB).compactionError

         0     0% 92.16%          3  5.88%  camlistore.org/third_party/github.com/syndtr/goleveldb/leveldb.(*DB).jWriter

         0     0% 92.16%          3  5.88%  camlistore.org/third_party/github.com/syndtr/goleveldb/leveldb.(*DB).mCompaction

         0     0% 92.16%          3  5.88%  camlistore.org/third_party/github.com/syndtr/goleveldb/leveldb.(*DB).mpoolDrain

         0     0% 92.16%          3  5.88%  camlistore.org/third_party/github.com/syndtr/goleveldb/leveldb.(*DB).tCompaction

         0     0% 92.16%          3  5.88%  camlistore.org/third_party/github.com/syndtr/goleveldb/leveldb/util.(*BufferPool).drain

         0     0% 92.16%          3  5.88%  runtime.chanrecv2

         0     0% 92.16%          2  3.92%  runtime.gcBgMarkWorker

         2  3.92% 96.08%          2  3.92%  runtime.notetsleepg

         0     0% 96.08%          1  1.96%  camlistore.org/pkg/importer.(*Host).AccountsStatus

         0     0% 96.08%          1  1.96%  camlistore.org/pkg/importer.(*importer).Accounts

         0     0% 96.08%          1  1.96%  camlistore.org/pkg/index.(*Corpus).EnumeratePermanodesCreatedLocked

Maybe goleveldb creates new goroutines which dies, in a loop???

Thanks,

Tamás Gulácsi