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If the persistent ring buffer is detected on boot up to have a corrupted sub-buffer, that sub-buffer is cleared to zero and its commit value has the RB_MISSED_EVENTS bit set. That bit is to allow the "trace", "trace_pipe" and "trace_pipe_raw" files know that events were dropped by outputting "[LOST EVENTS]". Only in this case does that bit get set in the writeable portion of the ring buffer. When events are dropped in the normal ring buffer, that information is stored in the cpu_buffer descriptor and the RB_MISSED_EVENTS is set in the buffer page at the time the page is consumed. It is never set in the writeable portion of the buffer. Add comments to describe this better as it can be confusing to know when the RB_MISSED_EVENTS are set in the commit portion of the buffer page. Link: https://lore.kernel.org/all/20260529001500.14178455a046a5cbc6180861@kernel.org/ Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://patch.msgid.link/20260528223738.41276c0e@fedora Signed-off-by: Steven Rostedt <rostedt@goodmis.org>