FAQ

Metrics

• Why do the memory_others_* metrics (e.g. directstall_time) have no data?

  The memory_others collector reads memory cgroup extension interfaces provided by the Didi Cloud custom kernel (memory.directstall_stat, memory.asynreclaim_stat, memory.local_direct_reclaim_time). Mainline and common distribution kernels do not expose these interfaces, and no loadable kernel module provides them, so these metrics are simply not emitted on standard kernels — this is expected behavior.

  To observe container direct reclaim behavior on standard kernels, use the eBPF-based memory_reclaim_container_directstall metric instead; see the Memory System section in “Key Features / Kernel-Wide Insight”.