On 24 Apr 2018, Dave Chinner said: > Yes, the problem still exists. CFQ just doesn't work well with > workloads that issue concurrent, dependent IOs from multiple > processes, nor does it work well with hardware raid arrays with > non-volatile caches that have unpredictable IO performance. This > sort of workload and hardware is common in the sorts of high > performance applications we see run on XFS filesystems, and we avoid > CFQ as much as possible.... Oh! I thought its problem was with concurrent *independent* I/Os. If it's fine with those, and you're using md (not hardware RAID) it sounds like the wost problems with CFQ may be avoided? (This is probably not too surprising in hindsight, since those are the characteristics of things like kernel compile runs, the one workload Linux will always work well with!) -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
