8258459: Decouple gc_globals.hpp from globals.hpp #1797

iklam · 2020-12-16T06:24:59Z

Currently, globals.hpp is including gc_globals.hpp. This exposes all the GC command-line flags to almost all cpp files. However, only about 1/3 of the cpp files would require gc_globals.hpp.

This RFE improves modularity and HotSpot build time.

Review notes:

Please start with globals.hpp, gc_globals.hpp.
Flags related to TLAB are frequently used by other header files. I moved these flags to a new header tlab_globals.hpp.
Some tweaking of oop.hpp to avoid including gc_globals.hpp in this popular header file. (Otherwise gc_globals.hpp would be included by everyone).
The other changes are just files that use GC flags. They should have included gc_globals.hpp but didn't.

Testing:
Tested with mach5: tier1, builds-tier2, builds-tier3, builds-tier4 and builds-tier5. Also locally: aarch64, arm, ppc64, s390, x86, and zero.

Progress

Change must not contain extraneous whitespace
Commit message must refer to an issue
Change must be properly reviewed

Issue

JDK-8258459: Decouple gc_globals.hpp from globals.hpp

Reviewers

Lois Foltan (@lfoltan - Reviewer) ⚠️ Review applies to df618db
Coleen Phillimore (@coleenp - Reviewer) ⚠️ Review applies to df618db

Download

$ git fetch https://git.openjdk.java.net/jdk pull/1797/head:pull/1797
$ git checkout pull/1797

bridgekeeper · 2020-12-16T06:25:53Z

👋 Welcome back iklam! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

openjdk · 2020-12-16T06:26:50Z

@iklam The following labels will be automatically applied to this pull request:

hotspot
shenandoah

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing lists. If you would like to change these labels, use the /label pull request command.

mlbridge · 2020-12-16T06:37:08Z

Webrevs

lfoltan

LGTM.
Lois

openjdk · 2020-12-16T15:43:23Z

@iklam This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8258459: Decouple gc_globals.hpp from globals.hpp

Reviewed-by: lfoltan, coleenp

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been no new commits pushed to the master branch. If another commit should be pushed before you perform the /integrate command, your PR will be automatically rebased. If you prefer to avoid any potential automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

coleenp

Looks good! I had a couple of minor change requests.

coleenp · 2020-12-22T13:07:51Z

src/hotspot/share/oops/oop.inline.hpp

@@ -185,7 +185,7 @@ int oopDesc::size_given_klass(Klass* klass)  {
      // disjunct below to fail if the two comparands are computed across such
      // a concurrent change.
      assert((s == klass->oop_size(this)) ||


It might be nicer to throw the second half of this assert into the .cpp file, like
assert(s == klass->oop_size(this) || gc_has_forwarded(), "wrong array object size");
With the special comment above it in the cpp file. Then someone has the potential to add more information if the assert fails, and that gets Universe::hpp out of the inline file (if that helps with future cleanups).

I'd like to keep this PR minimal. If I change (Universe::heap()->is_gc_active() && is_objArray() && is_forwarded() && (get_UseParallelGC() || get_UseG1GC()) to gc_has_forwarded(), I would also need to move the comments about UseParallelGC and UseG1GC can change the length field of an "old copy".... I think that should be done in a separate PR.

coleenp · 2020-12-22T13:08:23Z

src/hotspot/share/gc/shared/threadLocalAllocBuffer.cpp

@@ -58,6 +58,10 @@ ThreadLocalAllocBuffer::ThreadLocalAllocBuffer() :
  // do nothing. TLABs must be inited by initialize() calls
 }

+size_t ThreadLocalAllocBuffer::initial_refill_waste_limit()            { return desired_size() / TLABRefillWasteFraction; }


nit: please line this up.

…ls-hpp

iklam · 2021-01-05T05:56:48Z

Thanks @coleenp and @lfoltan for the review!
/integrate

openjdk · 2021-01-05T05:57:33Z

@iklam Pushed as commit 5ea9607.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

8258459: Decouple gc_globals.hpp from globals.hpp

665d209

openjdk bot added hotspot shenandoah labels Dec 16, 2020

fixed copyright year

df618db

iklam marked this pull request as ready for review December 16, 2020 06:33

openjdk bot added the rfr label Dec 16, 2020

lfoltan approved these changes Dec 16, 2020

View reviewed changes

openjdk bot added the ready label Dec 16, 2020

coleenp approved these changes Dec 22, 2020

View reviewed changes

iklam added 5 commits January 4, 2021 09:29

comments by coleenp

b3d4304

Merge branch 'master' into 8258459-decouple-gc-globals-hpp-from-globa…

28a4a5d

…ls-hpp

fixed copyright year

ec8a390

added tlab_globals.hpp to all files that use the TLAB globals

372fd80

Merge branch 'master' into 8258459-decouple-gc-globals-hpp-from-globa…

f68aa0e

…ls-hpp

openjdk bot closed this Jan 5, 2021

openjdk bot added integrated and removed ready rfr labels Jan 5, 2021

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

8258459: Decouple gc_globals.hpp from globals.hpp #1797

8258459: Decouple gc_globals.hpp from globals.hpp #1797

iklam commented Dec 16, 2020 •

edited by openjdk bot

Loading

bridgekeeper bot commented Dec 16, 2020

openjdk bot commented Dec 16, 2020

mlbridge bot commented Dec 16, 2020 •

edited

Loading

lfoltan left a comment

openjdk bot commented Dec 16, 2020 •

edited

Loading

coleenp left a comment

coleenp Dec 22, 2020

iklam Jan 4, 2021

coleenp Dec 22, 2020

iklam Jan 4, 2021

iklam commented Jan 5, 2021

openjdk bot commented Jan 5, 2021

8258459: Decouple gc_globals.hpp from globals.hpp #1797

8258459: Decouple gc_globals.hpp from globals.hpp #1797

Conversation

iklam commented Dec 16, 2020 • edited by openjdk bot Loading

Progress

Issue

Reviewers

Download

bridgekeeper bot commented Dec 16, 2020

openjdk bot commented Dec 16, 2020

mlbridge bot commented Dec 16, 2020 • edited Loading

Webrevs

lfoltan left a comment

Choose a reason for hiding this comment

openjdk bot commented Dec 16, 2020 • edited Loading

coleenp left a comment

Choose a reason for hiding this comment

coleenp Dec 22, 2020

Choose a reason for hiding this comment

iklam Jan 4, 2021

Choose a reason for hiding this comment

coleenp Dec 22, 2020

Choose a reason for hiding this comment

iklam Jan 4, 2021

Choose a reason for hiding this comment

iklam commented Jan 5, 2021

openjdk bot commented Jan 5, 2021

iklam commented Dec 16, 2020 •

edited by openjdk bot

Loading

mlbridge bot commented Dec 16, 2020 •

edited

Loading

openjdk bot commented Dec 16, 2020 •

edited

Loading