mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
synced 2025-01-09 15:29:16 +00:00
0b39920b5f
To support hierarchical stats, it's necessary to remember stats from dead children. Add cfqg->dead_stats and make a dying cfqg transfer its stats to the parent's dead-stats. The transfer happens form ->pd_offline_fn() and it is possible that there are some residual IOs completing afterwards. Currently, we lose these stats. Given that cgroup removal isn't a very high frequency operation and the amount of residual IOs on offline are likely to be nil or small, this shouldn't be a big deal and the complexity needed to handle residual IOs - another callback and rather elaborate synchronization to reach and lock the matching q - doesn't seem justified. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>