Re: [PATCH BUGFIX/IMPROVEMENT V2 0/3] three bfq fixes restoring service guarantees with random sync writes in bg
From: Mel Gorman
Date: Thu Aug 31 2017 - 10:43:41 EST
On Thu, Aug 31, 2017 at 08:46:28AM +0200, 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.
>
Queued on top of Ming's most recent series even though that's still a work
in progress. I should know in a few days how things stand.
--
Mel Gorman
SUSE Labs