JDK-8233535 : Distinguish page not yet faulted in case at os::numa_get_group_id_for_address()
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 14
  • Priority: P4
  • Status: Open
  • Resolution: Unresolved
  • OS: linux
  • Submitted: 2019-11-04
  • Updated: 2019-11-06
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tbdUnresolved
Related Reports
Relates :  
JDK-8220312 - Implementation: NUMA-Aware Memory Allocation for G1, Logging (3/3)
Description
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 of JDK-8220312.