Debugging with OProfile and Perf-events

Registered by Duncan McGreggor on 2010-03-26

Ensure that relevant patches (for perf events and oprofile) are in the release kernel tree(s)
Rally future efforts around this support, for example BSPs
Generate appropriate blueprints/specs for specific areas of development

Blueprint information

Status:
Started
Approver:
Loïc Minier
Priority:
Essential
Drafter:
Will Deacon
Direction:
Needs approval
Assignee:
Will Deacon
Definition:
Review
Series goal:
Accepted for maverick
Implementation:
Good progress
Milestone target:
milestone icon ubuntu-10.10-beta
Started by
Will Deacon on 2010-06-02

Related branches

Sprints

Whiteboard

Status:
Kernel work complete. Userspace [tool] work in progress.

[dave-martin-arm]: Investigating the perf tools, it looks like supprt for loading separated debug symbols is there, but it has a bug which prevents the symbols being loaded for images under the current directory when running perf report. I'm polling the upstream guys for feedback on the best way to fix this.

Work items (maverick-alpha-2):
[will-deacon] Update OProfile userspace tools: DONE
[will-deacon] Describe BSP modifications required for perf support on wiki page: DONE
[will-deacon] Check if vmlinux file is required for profiling Kernel code with OProfile: DONE

Work items (maverick-alpha-3):
[will-deacon] Enable HAVE_REGS_AND_STACK_ACCESS_API for ARM Linux Kernel in order to support perf probe: DONE
[lool] Enable building of linux-tools package for armel targets: DONE
[dave-martin-arm] Teach perf tools to extract debug information from ddebs: DONE
Investigate the potential for cross-profiling [in particular, where the debug symbols / binary are placed]: TODO

Work items (ubuntu-10.10-beta):
[dave-martin-arm] Clean up perf tools ddebs patch to work right: DONE
Validate code on supported ARMv7A platforms (note - only done for vexpress): DONE

[jamiebennett 2010-06-01] Need to make sure that this code is validated on appropriate ARMv7A hardware.

[dmart] For discussion:
   * Can the perfevents stuff be backported as an SRU to lucid?
   * How to get symbol-level profiling information? (are debug symbols / unstripped binaries required)
     [will-deacon]: Oprofile needs a vmlinux for Kernel symbol lookup.

[asac 22 Jun 10] massaging this spec a bit to have have concrete scheduling of work items; overall spec is targetted for alpha-3; the validation part is a QA/bug fix task and as that it can go to implemented before thats done.

(?)

Work Items