On Wed, 2019-01-30 at 12:21 -0700, Jason Gunthorpe wrote: +AD4 On Wed, Jan 30, 2019 at 10:59:34AM -0800, Bart Van Assche wrote: +AD4 +AD4 On Tue, 2019-01-22 at 10:25 -0800, Bart Van Assche wrote: +AD4 +AD4 +AD4 The default behavior of the SCSI core is to set the block layer request +AD4 +AD4 +AD4 queue parameter max+AF8-segment+AF8-size to 64 KB. That means that elements of +AD4 +AD4 +AD4 scatterlists are limited to 64 KB. Since RDMA adapters support larger +AD4 +AD4 +AD4 sizes, increase max+AF8-segment+AF8-size for the SRP initiator. +AD4 +AD4 +AD4 +AD4 +AD4 +AD4 Notes: +AD4 +AD4 +AD4 - The SCSI max+AF8-segment+AF8-size parameter was introduced in kernel v5.0. See +AD4 +AD4 +AD4 also commit 50c2e9107f17 (+ACI-scsi: introduce a max+AF8-segment+AF8-size +AD4 +AD4 +AD4 host+AF8-template parameters+ACI). +AD4 +AD4 +AD4 - Some other block drivers already set max+AF8-segment+AF8-size to UINT+AF8-MAX, +AD4 +AD4 +AD4 e.g. nbd and rbd. +AD4 +AD4 +AD4 +AD4 Hi Jason and Doug, +AD4 +AD4 +AD4 +AD4 Can one of you have a look at this patch? +AD4 +AD4 I was confused by the unanswered remark from Doug Gilbert - what that +AD4 a request to change something? Hi Jason, My understanding is that Doug Gilbert's e-mail was not a request to change my patch but instead an announcement of something he plans to implement in the future. The functionality Doug mentioned seems useful to me but does not replace this patch. It is much easier to users to have the default set correctly instead of having to modify the default from the command line or from a udev rule. Thanks, Bart.
