On Fri, Aug 20, 2010 at 9:49 AM, Bernd Schubert <bs_li...@aakef.fastmail.fm> wrote: > > In ib_srp.c sg_tablesize is defined as 255. With that value we see lots of IO > requests of size 1020. As I already wrote on linux-scsi, that is really sub- > optimal for DDN storage, as lots of IO requests of size 1020 come up. > > Now the question is if we can safely increase it. Is there somewhere a > definition what is the real hardware supported size? And shouldn't we increase > sg_tablesize, but also set the .dma_boundary value?
(resending as plain text) The request size of 1020 indicates that there are less than 60 data buffer descriptors in the SRP_CMD request. So you are probably hitting another limit than srp_sg_tablesize. Did this occur with buffered (asynchronous) or unbuffered (direct) I/O ? And in the first case, which I/O scheduler did you use ? Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
