x/build/cmd/buildlet: dragonflybsd buildlet extremely slow writing the source tar

[timdarbydotnet]

This example is typical:

Events:
2018-08-23T15:54:46Z checking_for_snapshot
2018-08-23T15:54:46Z finish_checking_for_snapshot after 0s
2018-08-23T15:54:46Z get_buildlet
2018-08-23T15:54:46Z wait_static_builder host-dragonfly-amd64-tdfbsd
2018-08-23T15:54:46Z waiting_machine_in_use
2018-08-25T15:37:00Z finish_wait_static_builder after 47h42m13.8s; host-dragonfly-amd64-tdfbsd
2018-08-25T15:37:00Z clean_buildlet http://dragonflybsd-amd64 reverse peer dragonflybsd-amd64/10.240.0.4:54535 for host type host-dragonfly-amd64-tdfbsd
2018-08-25T15:37:01Z finish_clean_buildlet after 64.8ms; http://dragonflybsd-amd64 reverse peer dragonflybsd-amd64/10.240.0.4:54535 for host type host-dragonfly-amd64-tdfbsd
2018-08-25T15:37:01Z finish_get_buildlet after 47h42m14.1s
2018-08-25T15:37:01Z using_buildlet dragonflybsd-amd64
2018-08-25T15:37:01Z write_version_tar
2018-08-25T15:37:01Z get_source
2018-08-25T15:37:01Z finish_get_source after 0s
2018-08-25T15:37:01Z write_go_src_tar
2018-08-25T15:53:17Z finish_write_go_src_tar after 16m16.2s
2018-08-25T15:53:17Z make_and_test
2018-08-25T15:53:17Z make src/make.bash

What could account for a 16 minute duration for this?

[bradfitz]

It extracts it as it reads from the network, so it might also be networking problems.

Is your -workdir on a spinny disk? You could move it to a tmpfs or other memory filesystem instead of using a real filesystem.

[bradfitz]

/cc @dmitshur

[timdarbydotnet]

It's using tmpfs, so that shouldn't be slowing it down.

[timdarbydotnet]

This builder used to be on a VM, but now it's on a physical machine with a 60 Mbps internet connection.

[timdarbydotnet]

I'm not seeing this now and not sure what fixed it, so closing the ticket