Re: [PATCH BUGFIX/IMPROVEMENT V2 0/3] three bfq fixes restoring service guarantees with random sync writes in bg

[Jens Axboe]

On 08/31/2017 12:46 AM, Paolo Valente wrote:
> [SECOND TAKE, with just the name of one of the tester fixed]
> 
> Hi,
> while testing the read-write unfairness issues reported by Mel, I
> found BFQ failing to guarantee good responsiveness against heavy
> random sync writes in the background, i.e., multiple writers doing
> random writes and systematic fdatasync [1]. The failure was caused by
> three related bugs, because of which BFQ failed to guarantee to
> high-weight processes the expected fraction of the throughput.
> 
> The three patches in this series fix these bugs. These fixes restore
> the usual BFQ service guarantees (and thus optimal responsiveness
> too), against the above background workload and, probably, against
> other similar workloads.

Applied for 4.14, thanks Paolo.

-- 
Jens Axboe