Re: splitting iovecs to bios

2015-12-13 Thread Sagi Grimberg
Hi Konstantin, There might be indeed a reason, it could be that some drivers expect blocking to be done by the userspace. The drivers could have some restrictions on transfer sizes and atomicity of transfer, which would be broken by the unconditional merge. I cannot give you an example of such

Re: splitting iovecs to bios

2015-12-10 Thread Konstantin Belousov
On Thu, Dec 10, 2015 at 02:20:19PM +0200, Max Gurtovoy wrote: > Hi all, > > I'm developing an iSER (iSCSI extensions for RDMA) driver for FreeBSD > 11-Current and I encounter some weired behaviour while testing IOs with > iovcnt > 1. > I wrote a small test program that creates an iovec struct (l

splitting iovecs to bios

2015-12-10 Thread Max Gurtovoy
Hi all, I'm developing an iSER (iSCSI extensions for RDMA) driver for FreeBSD 11-Current and I encounter some weired behaviour while testing IOs with iovcnt > 1. I wrote a small test program that creates an iovec struct (let's say in size of 4) and each iov_base starts from page begining and 4