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| author | Tejun Heo | 2013-01-09 08:05:13 -0800 |
|---|---|---|
| committer | Tejun Heo | 2013-01-09 08:05:13 -0800 |
| commit | 0b39920b5f9f3ad37dd259bfa2e9cbca33475b28 (patch) | |
| tree | 84f3c07ae535dbf02276ff3645b4fbfe95419d9b /Documentation/cpu-freq | |
| parent | 689665af4489f779bc82e7869509c9ac11b5a903 (diff) | |
cfq-iosched: collect stats from dead cfqgs
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>
Diffstat (limited to 'Documentation/cpu-freq')
0 files changed, 0 insertions, 0 deletions