Public bug reported: I've been running a locust[1]-based web load test on my Ubuntu machine running GNOME Shell (wayland). When starting a new test with a client spawn rate of ~500/s, it issues a huge amount of getaddrinfo() calls. When using libnss-resolve, this causes a huge number of NameOwnerChanged events on the system bus:
signal time=1506335482.865950 sender=org.freedesktop.DBus -> destination=(null destination) serial=227290 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged string ":1.190697" string "" string ":1.190697" signal time=1506335482.868601 sender=org.freedesktop.DBus -> destination=(null destination) serial=227291 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged string ":1.190697" string ":1.190697" string "" signal time=1506335483.305614 sender=org.freedesktop.DBus -> destination=(null destination) serial=227292 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged string ":1.190698" string "" string ":1.190698" signal time=1506335483.310873 sender=org.freedesktop.DBus -> destination=(null destination) serial=227293 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged string ":1.190698" string ":1.190698" string "" This in turn causes gnome-shell to spend a huge amount of CPU churning through these events, and if sufficiently starved of CPU (those load testing scripts also consume quite a bit) when interacting with Google Chome, it goes into key repeat runaway (similar to [2]). I'm not completely certain, but there were quite a number of other processes affected by this, and all of them start fighting over CPU time to handle these NameOnwerChanged events. As a workaround, disabling libnss-resolve in /etc/nsswitch.conf and just using the stub resolver fixes things. [1] https://locust.io [2] https://bugzilla.redhat.com/show_bug.cgi?id=1459692 ** Affects: systemd (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1719287 Title: libnss-resolve causes gnome-shell to hang when there's a high rate of getaddrinfo() calls To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1719287/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
