[lttng-dev] How much shared memory is used by LTTng (UST) ?

[Michel Dagenais]

> > It still doesn't explain why I was able to add procname to the
> > context but adding also vpid and vtid failed when the number of cores was 24
> > rather than 12.
> 
> No idea. These are unrelated.

Perhaps you were not tracing that much and not filling all buffers with the smaller events with less context? The kernel buffers are probably pre-allocated for real but other buffers in user-space may not.