Fixes a regression introduced in 80917a1054:
"scylla_prepare: stop generating 'mode' value in perftune.yaml"
When cpuset.conf contains a "full" CPU set the negation of it from
the "full" CPU set is going to generate a zero mask as a irq_cpu_mask.
This is an illegal value that will eventually end up in the generated
perftune.yaml, which in line will make the scylla service fail to start
until the issue is resolved.
In such a case a irq_cpu_mask must represent a "full" CPU set mimicking
a former 'MQ' mode.
\Fixes scylladb/scylladb#11701
Tested:
- Manually on a 2 vCPU VM in an 'auto-selection' mode.
- Manually on a large VM (48 vCPUs) with an 'MQ' manually
enforced.
Message-Id: <20221004004237.2961246-1-vladz@scylladb.com>
(cherry picked from commit 8195dab92a)
0d5751b4b6