On 05/07/14 19:19, Sagi Grimberg wrote: > On 5/7/2014 5:59 PM, Bart Van Assche wrote: >> On 05/07/14 13:34, Sagi Grimberg wrote: >>>> + pool = srp_create_fr_pool(dev->dev, dev->pd, >>>> + SRP_MDESC_PER_POOL, max_pages_per_mr); >>> 1024 FRMRs per connection?! we use 1024 FMRs for all connections >>> (per-device). I'd say that's a major over-allocation. >> It depends on how many discontiguous I/O requests are submitted >> concurrently. Anyway, how about limiting the number of memory regions to >> the queue size ? > > Perhaps, but we will need to reserve some more for discontinuous IOs. > It is heuristic, for FS in most cases IO will align nicely, for some > crazy DB applications - I'm not sure.
If srp_map_sg() runs out of memory descriptors it adds the remaining sg entries to the SRP indirect descriptor without using memory registration. In other words, I think a queue full of discontiguous I/O requests should be handled properly by srp_map_sg(). Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
