RE: [PATCH v2 06/33] Documentation, x86: Documentation for Intel resource allocation user interface

[Luck, Tony]

> I don't think this is convenient, but it's ok. Now if we create a new thread
> between 1 and 2, the new thread is in group1. The new thread pid isn't in the
> pid list we found in 1, so after 2, the new thread still is in group 1. Truely
> sysadmin can repeat the step 1 & 2 and move the new thread to group 2, but
> there is always chance the process creates new thread between 1 and 2, and the
> new thread remains in group 1. There is no guarantee we can safely move a
> process from one group to another.

In general this is true.  But don't most threaded applications have a single thread that
is the one that spawns new threads? Typically the first thread.  Once that is moved,
any new threads will inherit the new group. So there won't be a neverending mopping
operation trying to catch up.

Even this seems outside the expected usage model for CAT where we expect the
system admin to partition the cache between resource groups at boot time and
then assign jobs (or containers, or VMs) to resource groups when they are created.

-Tony