On Tue, 2 May 2023 15:53:17 GMT, Thomas Schatzl <tscha...@openjdk.org> wrote:
>> Hi all, >> >> please review this change that removes the pinned tag from `HeapRegion`. >> >> So that "pinned" tag for G1 heap regions indicates that the region should >> not move during (young) gc. This applies to now removed archive regions and >> humongous objects/regions. >> >> With "real" g1 region pinning to deal with gclocker in g1 once and for all >> upcoming we need a refcount, a single bit is not sufficient anymore. Further >> there will be a naming conflict as this kind of "pinning" is different to g1 >> region pinning "pinning". The former indicates "contents can not be moved, >> but can be reclaimed", while the latter means "contents can not be moved and >> not reclaimed". >> >> The (current) pinned flag is surprisingly little used, only for policy >> decisions. >> >> The suggestion this change implements is to remove the "pinned" tag as it >> is, and reserve it for future g1 region pinning (that needs to store the >> pinning attribute differently as a refcount anyway). >> >> Testing: tier1-3, gha >> >> Thanks, >> Thomas > > Thomas Schatzl has updated the pull request with a new target base due to a > merge or a rebase. The pull request now contains seven commits: > > - Merge branch 'master' into 8306836-remove-pinned-tag > - remove is_young_gc_movable in full gc code > - cplummer review > - ayang review > - Fix hsdb > - compilation fixes > - Initial implementation I removed the `young_gc_is_movable()` predicate; it is probably the wrong time to introduce more abstract concepts like this in this change. Moved off the refactoring of the `G1CollectionSetChooser::should_add()` and its caller to sometime else too - it's not relevant to this change either. ------------- PR Comment: https://git.openjdk.org/jdk/pull/13643#issuecomment-1531806113
