8338534: GenShen: Handle alloc failure differently when immediate garbage is pending

[kdnilsen]

trafficstars

Several changes are implemented here:

1. Re-order the phases that execute immediately after final-mark so that we do concurrent-cleanup quicker (but still after concurrent weak references)
2. After immediate garbage has been reclaimed by concurrent cleanup, notify waiting allocators
3. If an allocation failure occurs while immediate garbage recycling is pending, stall the allocation but do not cancel the concurrent gc.

---

Progress

• [x] Change must not contain extraneous whitespace
• [x] Commit message must refer to an issue
• [ ] Change must be properly reviewed (1 review required, with at least 1 Committer)

Issue

• JDK-8338534: GenShen: Handle alloc failure differently when immediate garbage is pending (Bug - P4)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/shenandoah.git pull/479/head:pull/479
$ git checkout pull/479

Update a local copy of the PR:
$ git checkout pull/479
$ git pull https://git.openjdk.org/shenandoah.git pull/479/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 479

View PR using the GUI difftool:
$ git pr show -t 479

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/shenandoah/pull/479.diff

Webrev

Link to Webrev Comment

[bridgekeeper[bot]]

:wave: Welcome back kdnilsen! 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[bot]]

❗ This change is not yet ready to be integrated. See the Progress checklist in the description for automated requirements.

[kdnilsen]

BTW, I can't figure out what jcheck whitespace is complaining about. I think it is reporting the wrong line number. jcheck on my local copy does not report a whitespace problem.

[ysramakrishna]

BTW, I can't figure out what jcheck whitespace is complaining about. I think it is reporting the wrong line number. jcheck on my local copy does not report a whitespace problem.

Yes, for some reason git jcheck -s doesn't find it.

However, there is indeed whitespace (in fact, 2 as in the error message) in that file on an otherwise blank line. However, the line number is indeed incorrect as you stated. It should be line 2467.

diff --git a/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp b/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
index cbcd22c053f..342c023d180 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
@@ -2464,7 +2464,7 @@ void ShenandoahHeap::rebuild_free_set(bool concurrent) {
   _free_set->prepare_to_rebuild(young_cset_regions, old_cset_regions, first_old_region, last_old_region, old_region_count);
   size_t anticipated_immediate_garbage = (old_cset_regions + young_cset_regions) * ShenandoahHeapRegion::region_size_words();
   control_thread()->anticipate_immediate_garbage(anticipated_immediate_garbage);
-  
+
   // If there are no old regions, first_old_region will be greater than last_old_region
   assert((first_old_region > last_old_region) ||
          ((last_old_region + 1 - first_old_region >= old_region_count) &&

[ysramakrishna]

% find . -type f -name "*pp" | xargs grep -n " $" 
./src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp:2467:  

[mlbridge[bot]]

Webrevs

• 00: Full (f11a3c81)

[bridgekeeper[bot]]

@kdnilsen This pull request has been inactive for more than 4 weeks and will be automatically closed if another 4 weeks passes without any activity. To avoid this, simply add a new comment to the pull request. Feel free to ask for assistance if you need help with progressing this pull request towards integration!

[ysramakrishna]

@kdnilsen : Should this become a draft for now?

[bridgekeeper[bot]]

@kdnilsen This pull request has been inactive for more than 4 weeks and will be automatically closed if another 4 weeks passes without any activity. To avoid this, simply add a new comment to the pull request. Feel free to ask for assistance if you need help with progressing this pull request towards integration!

[bridgekeeper[bot]]

@kdnilsen This pull request has been inactive for more than 8 weeks and will now be automatically closed. If you would like to continue working on this pull request in the future, feel free to reopen it! This can be done using the /open pull request command.