This patch introduces a kernel boot parameter to optionally disable the timer migration. On heterogeneous systems with big.LITTLE architectures, timer migration may cause timers from little cores to run on big cores, or vice versa, because core type differences are not considered in the current timer migration logic. In our heterogeneous system, we observed timers being migrated to big CPU frequently, resulting in timer callbacks that could have run on little CPUs being executed on the big CPU instead. This reduced big CPU's idle residency and increased overall power consumption due to higher power draw on the big CPU. Since timer_migration is a relatively new feature, addressing the structural limitation was difficult. Therefore, this patch adds a boot parameter to optionally disable timer migration. --- Changes in v2: - Added more description of potential issue in the commit message - Changed the boot parameter format to tmigr=[on|off] Link: https://lore.kernel.org/r/20250807064849.3988-1-sehee1.jeong@xxxxxxxxxxx Sehee Jeong (1): timers/migration: add 'tmigr' kernel parameter to optionally disable timer migration .../admin-guide/kernel-parameters.txt | 4 ++++ kernel/time/timer_migration.c | 19 +++++++++++++++++++ 2 files changed, 23 insertions(+) -- 2.49.0
