On Tue, 8 Jun 2021 08:17:54 GMT, Thomas Stuefe <stu...@openjdk.org> wrote:
>> Henry Jen has updated the pull request with a new target base due to a merge >> or a rebase. The incremental webrev excludes the unrelated changes brought >> in by the merge/rebase. The pull request contains seven additional commits >> since the last revision: >> >> - Cast type >> - Merge >> - Change java -X output for -Xss >> - Merge >> - Only try to round-up when current value failed >> - Avoid overflow on page size >> - JDK-8236569: -Xss not multiple of 4K does not work for the main thread on >> macOS > > src/java.base/unix/native/libjli/java_md.c line 666: > >> 664: return page_size * pages; >> 665: } >> 666: } > > Could probably be shortened to something like this: > > > size_t pagesize = (size_t)sysconf(_SC_PAGESIZE); > return (stack_size + (pagesize - 1)) & ~(pagesize - 1); > > > or, if you insist on checking for SIZE_MAX: > > > size_t pagesize = (size_t)sysconf(_SC_PAGESIZE); > size_t max = SIZE_MAX - pagesize; > return stack_size <= max ? (stack_size + (pagesize - 1)) & ~(pagesize - 1) : > max; > > > (I see David requested this, so this is fine, though passing SIZE_MAX to this > function will quite likely fail anyway :) While sysconf(_SC_PAGESIZE) is most likely(if not always) be power of 2, it's not a constant we know for sure here and this is not critical path for performance, thus I didn't take that approach. ------------- PR: https://git.openjdk.java.net/jdk/pull/4256
