On Fri, 8 Mar 2024 02:35:08 GMT, Man Cao <m...@openjdk.org> wrote: >> Hi all, >> >> Could anyone review this fix to make serial heap dump only write to a single >> file? >> We highly appreciate the work in >> https://bugs.openjdk.org/browse/JDK-8306441. However, many of our customers >> still need to use serial heap dump, as they have limited disk space and need >> to dump to a network socket. >> >> Tested: >> Stress tested with a fastdebug build with tests in >> `hotspot/jtreg/serviceability/dcmd/gc/HeapDump*`. >> >> -Man > > Man Cao has updated the pull request incrementally with one additional commit > since the last revision: > > Fix failure under -XX:+UseSerialGC
Right, global writer is used to write HPROF_FRAME/HPROF_TRACE records when unmounted VT is found in the heap. The spec does not require HPROF_FRAME/HPROF_TRACE to be in the beginning. Main concern here is compatibility as we don't control external hprof tools. Solution #2 looks better to me. It does not require extra memory to track unmounted VT (we may have millions) and it can prevent compatibility problem if we first write HPROF_FRAME/HPROF_TRACE records and then HPROF_GC_ROOT_THREAD_OBJ and stack reference subrecords which refer to the HPROF_TRACE ------------- PR Comment: https://git.openjdk.org/jdk/pull/18160#issuecomment-1986286463
