As the cpu-partitioning profile does not use isolcpus=,
the kernel can end up creating long living timers on
nohz_full CPUs during early boot. Those timers will
fire later, causing jitter.
However, recent Linux kernel will always try to migrate
unpinned timers away from nohz_full CPUs when timer
migration is enabled which is what we want.
NOTE: Older kernels would migrate unpinned timers from
idle CPUs to busy CPUs without regard if the
CPU is nohz_full. This would certainly cause
trouble to applications that takes 100% of the
CPU in user-space (eg. DPDK). So, enabling
timer migration is only safe on recent kernels.
Resolves: rhbz#1408308
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
11686d59fe