Currently os::numa_get_group_id_for_address() only returns 'valid NUMA id' or '-1'.
However returning 'not yet faulted in' value also may useful. The underlying implementation on Linux uses the syscall move_pages() and for addresses not yet faulted we get the status -EFAULT (for normal pages) or -ENOENT (for large pages) returned. We could use this information to return more detailed information from numa_get_group_id_for_address(), but we need to investigate the benefit of doing it.
This idea was brought up during code review ofJDK-8220312.
However returning 'not yet faulted in' value also may useful. The underlying implementation on Linux uses the syscall move_pages() and for addresses not yet faulted we get the status -EFAULT (for normal pages) or -ENOENT (for large pages) returned. We could use this information to return more detailed information from numa_get_group_id_for_address(), but we need to investigate the benefit of doing it.
This idea was brought up during code review of
- relates to
-
JDK-8220312 Implementation: NUMA-Aware Memory Allocation for G1, Logging (3/3)
-
- Resolved
-