By default, overprovisioned is not enabled on docker unless it is
explicitly set. I have come to believe that this is a mistake.
If the user is running alone in the machine, and there are no other
processes pinned anywhere - including interrupts - not running
overprovisioned is the best choice.
But everywhere else, it is not: even if a user runs 2 docker containers
in the same machine and statically partitions CPUs with --smp (but
without cpuset) the docker containers will pin themselves to the same
sets of CPU, as they are totally unaware of each other.
It is also very common, specially in some virtualized environments, for
interrupts not to be properly distributed - being particularly keen on
being delivered on CPU0, a CPU which Scylla will pin by default.
Lastly, environments like Kubernetes simply don't support pinning at the
moment.
This patch enables the overprovisioned flag if it is explicitly set -
like we did before - but also by default unless --cpuset is set.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <20180331142131.842-1-glauber@scylladb.com>
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