[PATCH BUGFIX/IMPROVEMENT 0/4] bfq: two fixes and one improvement related to I/O control

[Paolo Valente]

Hi Jens,

while working a little bit on cgroups I/O control, I found two nasty
bugs in bfq. They break bandwidth control in simple configurations
with one-process groups. These bugs are fixed by the first two patches
in this series.

These fixes improved I/O control so much, that I could reduce the
write overcharge factor, used by bfq to counter write-induced
issues. This reduction is performed by the third patch.

The fourth patch contains a little code improvement I made in a
function that has to do with I/O control.

I hope we are still in time for 4.19.

Thanks,
Paolo

Paolo Valente (4):
  block, bfq: readd missing reset of parent-entity service
  block, bfq: always update the budget of an entity when needed
  block, bfq: reduce write overcharge
  block, bfq: improve code of bfq_bfqq_charge_time

 block/bfq-iosched.c | 54 +++++++++++++++++++++++++++++++++++++++--------------
 block/bfq-wf2q.c    | 22 +++++++++++-----------
 2 files changed, 51 insertions(+), 25 deletions(-)

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2.16.1