On Wed 05-04-17 11:15:44, Raymond Jennings wrote: > I have 32GiB of memory > > Storage is an LVM volume group sitting on a pair of 2T western digital > drives, one WD Green, and the other WD Blue > > My CPU is an i7, model 4790K. > > What I'd like is some way for my system to fairly share the available > I/O bandwidth. My youtube is sensitive to latency but doesn't chew up > a lot of throughput. My I/O heavy stuff isn't really urgent and I > don't mind it yielding to the interactive stuff. > > I remember a similiar concept being tried awhile ago with a scheduler > that "punished" processes that sucked up too much CPU and made sure > the short sporadic event driven interactive stuff got the scraps of > CPU when it needed them. > > /proc/sys/vm/dirty is set up as follows > > dirty_ratio 90 So you allow 90% of your 32GB to be dirty and then get throttled which will take quite some time until it gets synced to the disk. Even with a fast storage. I would really recommend reducing dirty_ratio (and background ratio as well) to something much more reasonable. E.g. start the background IO at around 400MB and hard limit at 800MB. I am pretty sure that the stalls you are seeing are related to the IO dirty throttling. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
