> Il giorno 31 ago 2017, alle ore 08:41, oleksandr@xxxxxxxxxxxxxx ha scritto: > >> Tested-by: Oleksander Natalenko <oleksandr@xxxxxxxxxxxxxx> > > I'm "Oleksandr" :). > Sorry, resending ... Paolo > 31.08.2017 08:10, Paolo Valente wrote: >> 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. >> Thanks, >> Paolo >> [1] https://lkml.org/lkml/2017/8/9/957 >> Paolo Valente (3): >> block, bfq: make lookup_next_entity push up vtime on expirations >> block, bfq: remove direct switch to an entity in higher class >> block, bfq: guarantee update_next_in_service always returns an >> eligible entity >> block/bfq-iosched.c | 4 +-- >> block/bfq-iosched.h | 4 +-- >> block/bfq-wf2q.c | 91 ++++++++++++++++++++++++++++++++--------------------- >> 3 files changed, 60 insertions(+), 39 deletions(-) >> -- >> 2.10.0
