Memory Footprint
Discuss possibilities for reducing memory footprint to improve performance, and identify useful optimisations and investigations which should be carried out.
Blueprint information
- Status:
- Started
- Approver:
- Steve Langasek
- Priority:
- High
- Drafter:
- John Rigby
- Direction:
- Needs approval
- Assignee:
- Dave Martin
- Definition:
- Review
- Series goal:
- Accepted for maverick
- Implementation:
- Started
- Milestone target:
- ubuntu-10.10-beta
- Started by
- Dave Martin
- Completed by
Whiteboard
[dmart 2010-07-10]: Investigate mklibs is POSTPONED as vorlon reckons this isn't a promising line of enquiry for now -- not applicable to general-purpose environments)
[asac 22 Jun 10]: with davem being gone for a few weeks still, nothing will happen for alpha-2; targetting investigation items for alpha-3 and beta for implementation pieces accordingly. Please adjust and talk to me or approver if you think that targetting is completely off
Status:
Preliminary investigation is done; now focusing on manual profiling and basic bootchart integration to identify Ubuntu/linaro components which need attention. No systemic changes expected to land for 10.11.
Bootchart packages with experimental memory usage logging support can be found in Dave Martin's PPA: see
https:/
Work items (maverick-alpha-3):
[cjwatson] pointers on how to use compiler wrappers to achieve feedback-directed optimisation: DONE
[dave-martin-arm] investigate exmap-console, sar and frysk: DONE
[dave-martin-arm] investigate atop and smem: DONE
[guillaume-
[dave-martin-arm] investigate tools for dead code removal: POSTPONED
[dave-martin-arm] investigate how we could do coverage measurement to assess the amount of unused code/data in binaries: POSTPONED
[dave-martin-arm] investigate mklibs: POSTPONED
Work items (ubuntu-
[dave-martin-arm] investigate extending bootchart to measure memory usage: INPROGRESS
[dave-martin-arm] kernel tuning for optimised memory utilization: POSTPONED
[dave-martin-arm] determine which reduction efforts should go into Maverick: DONE
[dave-martin-arm] document what reduction efforts should be investigated in Maverick+1: TODO
[dave-martin-arm] select target profile: DONE
[dave-martin-arm] define "memory footprint": DONE
Work items (ubuntu-10.10):
[dave-martin-arm] investigate compiler options (-Os): DONE
Later work items:
[richard-earnshaw] follow up with codesourcery about memory optimisation including hot/cold partitioning support: TODO
[richard-earnshaw] follow up on: http://
Even later work items:
[paul-e-mckenney] merge SRCU into tree/tiny implementations (should reduce memory footprint, especially for UP kernels): TODO
Removed work items:
[dave-martin-arm] investigate the maemo sp-memusage and sp-smaps packages for integration in linaro+ubuntu [will revisit later if useful, but we have enough basic tools in Ubuntu for now]
[paul-e-mckenney] tiny implementation of preemptible RCU (currently only large-memory-
[paul-e-mckenney] preemptible RCU priority boosting (reduce memory footprint due to preempted RCU readers): [Moved to https:/
Work Items
Dependency tree
* Blueprints in grey have been implemented.