Set the rebalance thread's scheduling class to BATCH, which means it could experience a higher scheduling latency. However, it reduces preemption events of running threads.
And while the rebalance thread is ually not compute bound, it does cause a considerable amount of I/O. By increasing its nice level from 0 to 19 we also implicitly reduce the thread's best-effort I/O scheduling class level from 4 to 7. Therefore, the rebalance thread's I/O operations will be deprioritized over standard I/O operations. Signed-off-by: Florian Schmaus <[email protected]> --- fs/bcachefs/rebalance.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/bcachefs/rebalance.c b/fs/bcachefs/rebalance.c index 4adc74cd3f70..b26c68007c5a 100644 --- a/fs/bcachefs/rebalance.c +++ b/fs/bcachefs/rebalance.c @@ -22,6 +22,7 @@ #include <linux/freezer.h> #include <linux/kthread.h> +#include <linux/sched.h> #include <linux/sched/cputime.h> /* bch_extent_rebalance: */ @@ -662,6 +663,8 @@ int bch2_rebalance_start(struct bch_fs *c) if (ret) return ret; + sched_set_batch(p, 19); + get_task_struct(p); rcu_assign_pointer(c->rebalance.thread, p); wake_up_process(p); -- 2.45.2
