Mir

Mir wastes lots of threads and resources on the "frontend thread pool"

Bug #1233001 reported by Daniel van Vugt
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Mir
Fix Released
Medium
Alan Griffiths
Unity System Compositor
Medium
Daniel van Vugt
mir (Ubuntu)
Medium
Unassigned

Bug Description

Mir wastes lots of threads and resources on the "frontend thread pool".

It is 10 threads by default, always running and almost always sleeping. As far as I know, this is the set of threads that handles incoming requests. However:

  1. A thread always occupies a minimum of 8MB address space for its stack, not to mention other resources.
  2. Even when I reduce the number of frontend threads to 1 (--ipc-thread-pool 1), Mir still seems to handle multiple simultaneous clients without missing a beat.
  3. unity-system-compositor will generally only ever have one or two clients. Yet it too wastes 10 threads on the frontend thread pool.

So we need to fix two things at least:

(a) Our primary Mir server "unity-system-compositor" needs a more sane default for XMir, as in only one IPC thread.
(b) All Mir servers via libmirserver should be more sensible with threads. Only creating them as required, if required.

Related branches

tags: added: performance
Changed in unity-system-compositor:
assignee: nobody → Daniel van Vugt (vanvugt)
Revision history for this message
PS Jenkins bot (ps-jenkins) wrote :

Fix committed into lp:~mir-team/mir/development-branch at revision 1110, scheduled for release in mir, milestone Unknown

Changed in mir:
status: New → Fix Committed
Changed in mir:
status: Fix Committed → Triaged
Changed in unity-system-compositor:
status: New → Triaged
Changed in mir:
importance: Undecided → Medium
Changed in unity-system-compositor:
importance: Undecided → Medium
Changed in mir:
status: Triaged → In Progress
assignee: nobody → Alan Griffiths (alan-griffiths)
milestone: none → 0.1.5
Changed in mir:
milestone: 0.1.5 → 0.1.6
Revision history for this message
PS Jenkins bot (ps-jenkins) wrote :

Fix committed into lp:mir/devel at revision None, scheduled for release in mir, milestone Unknown

Changed in mir:
status: In Progress → Fix Committed
Revision history for this message
Daniel van Vugt (vanvugt) wrote :

Now invalid for USC. The same fix I had planned is in Mir instead.

Changed in unity-system-compositor:
status: Triaged → Won't Fix
status: Won't Fix → Invalid
Changed in mir:
status: Fix Committed → Fix Released
Revision history for this message
Daniel van Vugt (vanvugt) wrote :

This bug was fixed in the package mir - 0.1.6+14.04.20140310-0ubuntu1
---------------
mir (0.1.6+14.04.20140310-0ubuntu1) trusty; urgency=medium

Changed in mir (Ubuntu):
importance: Undecided → Medium
status: New → Fix Released
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