1563403 - Local PGO builds should use 3-tier machinery instead of a custom Makefile target

Status: RESOLVED FIXED

(Firefox Build System :: General, task)

Description

[Michael Shal [:mshal]]

Local developers still need a way to trigger a full stack of PGO builds, but we could manage this internally via the 3-tier PGO machinery instead of the profiledbuild:: Makefile target (and relevant make variables).

For this bug, we should focus on just making the full stack mostly consistent with what happens today, perhaps still triggered by setting MOZ_PGO=1 in the environment. In the future we can add alternative workflows that pull an instrumented build or profile data from automation to skip some of the tiers.

Comment 1

[Michael Shal [:mshal]]

Attachment: Bug 1563403 - disable LTO on --enable-profile-generate; r?#firefox-build-system-reviewers

In automation this is normally handled by mozconfigs, but we should
disable it automatically during the profile-generate stage for users if
they have LTO enabled in their mozconfig while doing a 3-tier PGO build.

Comment 2

[Michael Shal [:mshal]]

Attachment: Bug 1563403 - Use 3-tier PGO for local MOZ_PGO=1 builds; r?#firefox-build-system-reviewers,dmajor

Local PGO builds now use 3-tier machinery under the hood. Instead of a
single object directory that gets cleaned in between the instrumented
and profile-use builds, now the instrumented build uses a separate
'${objdir}-instrumented' directory. This makes it easier to handle
within mach since we can drive the two builds with environment variables
and keep all build artifacts separate, without needing to do manual
cleanup in between.

Depends on D50097

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/17c3d10bb8dd
disable LTO on --enable-profile-generate; r=firefox-build-system-reviewers,chmanchester
https://hg.mozilla.org/integration/autoland/rev/ad679d570e52
Use 3-tier PGO for local MOZ_PGO=1 builds; r=firefox-build-system-reviewers,dmajor,chmanchester

Comment 4

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/17c3d10bb8dd
https://hg.mozilla.org/mozilla-central/rev/ad679d570e52