CMS: BOT walkers observe out-of-thin-air zeros on sun4v sparc/CMT

XMLWordPrintable

    • Type: Bug
    • Resolution: Fixed
    • Priority: P2
    • hs19
    • Affects Version/s: hs17, 6u19
    • Component/s: hotspot
    • gc
    • 1.4.2
    • b01
    • sparc
    • solaris, solaris_10
    • Verified

        BOT bulk-updates use memset(). However on Niagara memset() uses BIS
        for speed and this exposes concurrent readers to out-of-thin-air zeroes,
        which are fatal for concurrent BOT walks. Such concurrent reads of
        BOT entries subject to concurrent update are possible with non-contiguous
        spaces such as CMS (but not any other current GC in HotSpot).

              Assignee:
              Y. Ramakrishna
              Reporter:
              Y. Ramakrishna
              Votes:
              0 Vote for this issue
              Watchers:
              4 Start watching this issue

                Created:
                Updated:
                Resolved:
                Imported:
                Indexed: