Hello, On Wed, Nov 30, 2016 at 10:14:50AM -0800, Linus Torvalds wrote: > Tejun/Kent - any way to just limit the workqueue depth for bcache? > Because that really isn't helping, and things *will* time out and > cause those problems when you have hundreds of IO's queued on a disk > that likely as a write iops around ~100..
Yeah, easily. I'm assuming it's gonna be the bcache_wq allocated in from bcache_init(). It's currently using 0 as @max_active and it can set to be any arbitrary number. It'd be a very crude way to control what looks like a buffer bloat with IOs tho. We can make it a bit more granular by splitting workqueues per bcache instance / purpose but for the long term the right solution seems to be hooking into writeback throttling mechanism that block layer just grew recently. Thanks. -- tejun