On Wed, Nov 27, 2019 at 10:00 AM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > On Tue, Nov 26, 2019 at 12:17:15PM +0100, Hannes Reinecke wrote: > If requests are batched enough we could just drain > and switch every time an other partition access comes in. Especially > so if people only use partitions for boot partitions and other rarely > used areas. We only support a single user partition plus up to two boot partitions that are accessed rarely, I don't think there is any reason to optimize switching between them. The only change that I think we need here is to change the partition switch from something that is done synchronously during ->queue_rq() to something that fits better into normal scheme of sending a cmd to the device, returning BLK_STS_RESOURCE from ->queue_rq. Possibly this could even be turned into a standard struct request that is added between two normal requests for different partitions at some point, if this simplifies the logic (I suspect it won't, but it may be worth a try). Arnd