On Tue, Jun 30, 2015 at 3:47 PM, Craig Watson <craig.watson@xxxxxxxxxxxxxxxxxxx> wrote: > I recently ran a test on a LIO target system. I used a Windows 7 Pro box > with an ATTO card running iometer (www.iometer.org) hooked to a Linux target > running kernel 4.0.4 with a QLE-2562. Just doing a read with a 5MB transfer > size fails! I thought this was all fixed with commit > "11e764bd5ed4bb930e0ec5dd161df58307507347, 09-May-2012, Nicholas Bellinger > target: Remove max_sectors device attribute for modern se_task less code" > and maybe commit "046ba64285a4389ae5e9a7dfa253c6bff3d7c341, 07-Jan-2015, > Nicholas Bellinger target: Drop arbitrary maximum I/O size limit" (and a few > others)? Yeah, those commits don't really make sense. The qlogic hardware really has a limit on the number of gather/scatter entries a descriptor can have, so given the LIO model of executing IOs in a single chunk, there really is a size limit on commands that qla2xxx can handle. As far as I know, the only way to raise this limit is to implement handling for doing partial commands. In other words, for a 30MB read, break it up into 1MB reads and return each 1MB with a separate qla2xxx HW descriptor. - R. -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
