kernel-rt: config: disable SLUB_CPU_PARTIAL for real time kernels

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2182930
Upstream Status: RHEL only

The SLUB allocator (used by the RT kernel) uses deferred kfree()
processing by default.

When cpu_partial logic kicks in to reclaim deferred kfree() blocks,
latency spikes can be observed. The cpu partials are protected by a
spinlock and can create high latencies when all cpus contend on the
lock.

Partial processing is an optimization and can be turned off in favor of
determinism. That has been the case on kernel-rt for a while now.

Signed-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>

Author: lclaudio

redhat/configs/ark/rt/CONFIG_SLUB_CPU_PARTIAL

@@ -0,0 +1 @@
+# CONFIG_SLUB_CPU_PARTIAL is not set