contents/understanding-lttng/core-concepts/channel/channel-buffering-schemes.md

   1 ---
   2 id: channel-buffering-schemes
   3 ---
   4
   5 In the user space tracing domain, two **buffering schemes** are
   6 available when creating a channel:
   7
   8   * **Per-PID buffering**: keep one ring buffer per process.
   9   * **Per-UID buffering**: keep one ring buffer for all processes of
  10     a single user.
  11
  12 The per-PID buffering scheme consumes more memory than the per-UID
  13 option if more than one process is instrumented for LTTng-UST. However,
  14 per-PID buffering ensures that one process having a high event
  15 throughput won't fill all the shared sub-buffers, only its own.
  16
  17 The Linux kernel tracing domain only has one available buffering scheme
  18 which is to use a single ring buffer for the whole system.