Profiler driven feedback

Registered by Michael Hope

Ensure profiler driven feedback works with ARM.

Blueprint information

Status:
Complete
Approver:
Michael Hope
Priority:
Medium
Drafter:
Ulrich Weigand
Direction:
Needs approval
Assignee:
Michael Hope
Definition:
Approved
Series goal:
Accepted for 4.6
Implementation:
Implemented
Milestone target:
None
Started by
Ulrich Weigand
Completed by
Michael Hope

Related branches

Sprints

Whiteboard

From the summit:
 - Python is the best target for this, but PGO building is currently fragile
   - Gives 5-6% increase in some benchmark
 - Packaging has issues. Can generate a profile manually (eg in-tree build with -fprofile-dir, -fprofile-generate/run), shove into debian folder and use -fprofile-use in debian/rules)

Priority is set based on effort vs reward. The performance people may choose to pick this up.

gcc-linaro-4.6 now passes a PGO build. Postponed the 'show it improves' until we do the investigation on PGO as a theme.

See also LP: #598462. Unlinked as status.l.o shows 'todo' for a wont-fix.

Effort: 1-3M

(?)

Work Items

Work items:
Verify python profiled package build in Natty: DONE
Verify Linaro GCC profiled bootstrap: DONE
Discuss PGO support statement with Ubuntu: DONE
[michaelh1] Enable profiledbootstrap for continuous build: DONE
[michaelh1] Demonstrate that it improves things: POSTPONED

Dependency tree

* Blueprints in grey have been implemented.

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