On 11/15/24 10:45 AM, Michal Koutný wrote:
Hello.
On Fri, Nov 08, 2024 at 07:48:30AM GMT, Costa Shulyupin <costa.shul@xxxxxxxxxx> wrote:
Cgroups allow configuring isolated_cpus at runtime.
However, blk-mq may still use managed interrupts on the
newly isolated CPUs.
Rebuild hctx->cpumask considering isolated CPUs to avoid
managed interrupts on those CPUs and reclaim non-isolated ones.
The patch is based on
isolation: Exclude dynamically isolated CPUs from housekeeping masks:
https://lore.kernel.org/lkml/20240821142312.236970-1-longman@xxxxxxxxxx/
Even based on that this seems incomplete to me the CPUs that are part of
isolcpus mask on boot time won't be excluded from this?
IOW, isolating CPUs from blk_mq_hw_ctx would only be possible via cpuset
but not "statically" throught the cmdline option, or would it?
The cpuset had already been changed to take note of the statically
isolated CPUs and included them in its consideration. They are recorded
in the boot_hk_cpus mask. It relies on the fact that most users will set
both nohz_full and isolcpus boot parameters. If only nohz_full is set
without isolcpus, it will not be recorded.
Cheers,
Longman
