Caché Monitoring Guide - InterSystems Documentation

Considering Seizes, ASeizes, and NSeizes
resource for other processes that may be waiting for it; this is an Aseize. If, at the end of the hold loop, the resource is still
held by another process, the process continues to hibernate and wait to be woken up when the resource is released; this is
an Nseize.
Nseizes are a natural consequence of running multiple processes on a single-CPU system; Aseizes are a natural consequence
of running multiple processes on a multi-CPU system. The difference is that Nseizes incur system, or privileged, CPU time
because the operating system must change the context of the running process, whereas an Aseize incurs user time on the
CPU because it continues to run until the resource is gained and released, or until it gives up and hibernates. In general, on
multi-CPU systems it is more expensive for the operating system to do the context switch than to loop a few times to avoid
this operation because there is both CPU overhead and memory latency associated with context switching on multi-CPU
systems.
Caché Monitoring Guide 91