[PATCH BUGFIX/IMPROVEMENT 0/2] block, bfq: two pending patches

[Paolo Valente]

Hi Jens,
here are again the two pending patches you asked me to resend [1]. One
of them, fixing read-starvation problems, was accompanied by a cover
letter. I'm pasting the content of that cover letter below.

The patch addresses (serious) starvation problems caused by
request-tag exhaustion, as explained in more detail in the commit
message. I started from the solution in the function
kyber_limit_depth, but then I had to define more articulate limits, to
counter starvation also in cases not covered in kyber_limit_depth.
If this solution proves to be effective, I'm willing to port it
somehow to the other schedulers.

Thanks,
Paolo

[1] https://www.spinics.net/lists/linux-block/msg21586.html

Paolo Valente (2):
  block, bfq: limit tags for writes and async I/O
  block, bfq: limit sectors served with interactive weight raising

 block/bfq-iosched.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++++---
 block/bfq-iosched.h |  17 ++++++
 block/bfq-wf2q.c    |   3 +
 3 files changed, 169 insertions(+), 9 deletions(-)

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2.15.1