Am Donnerstag, den 20.06.2019, 07:10 -0700 schrieb Tejun Heo: > Hello, > > On Tue, Jun 18, 2019 at 11:59:39AM -0400, Alan Stern wrote: > > > > Even if you disagree, perhaps we should have a global workqueue with a > > > > permanently set noio flag. It could be shared among multiple drivers > > > > such as uas and the hub driver for purposes like this. (In fact, the > > > > hub driver already has its own dedicated workqueue.) > > > > > > That is a good idea. But does UAS need WQ_MEM_RECLAIM? > > > > These are good questions, and I don't have the answers. Perhaps Tejun > > or someone else on LKML can help. > > Any device which may host a filesystem or swap needs to use > WQ_MEM_RECLAIM workqueues on anything which may be used during normal > IOs including e.g. error handling which may be invoked. One > WQ_MEM_RECLAIM workqueue guarantees one level of concurrency for all > its tasks regardless of memory situation, so as long as there's no > interdependence between work items, the workqueue can be shared. Ouch. Alan, in that case anything doing a reset, suspend or resume needs to use WQ_MEM_RECLAIM, it looks to me. What do we do? Regards Oliver
