On Mon, Mar 3, 2008 at 8:42 AM, James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote: > > On Fri, 2008-02-29 at 12:01 -0600, James Bottomley wrote: > > I noticed that the current marvell sas driver wasn't performing very > > well. It turns out that it's setting can_queue not in the SCSI host, > > but in its own internal data structure, meaning it's always operating > > with a global queue depth of one. This patch raises it to what the code > > seemed to be intending ... although I think can_queue should be > > MVS_CHIP_SLOT_SZ - 1 (without the divide by two)? > > > > The good news is that with this change, I'm getting a respectable > > throughput on the fio hammer test; plus zapping random phy resets across > > the disk triggers error handler recovery correctly (so far). > > > > I'm having less happy results with a SATAPI DVD ... it looks like the > > initial IDENTIFY goes across just fine, but that we stall on the other > > SCSI commands ... I'm still investigating this one. > > Actually, I've run into another problem with this patch applied. It > looks like NCQ fails with ATA disks. What I see is that I/O goes fine > until I get more than one command outstanding to the device, then the > device stops responding. I can keep the I/O flowing if I clamp the > device queue depth at 1. SAS disks seem to be fine ... I can get > multiple outstanding commands to them correctly serviced. Yes, I have to say that testing failed when I plugged SATA and SAS disk. Sometimes "insmod mvsas" will cause the system to hang. Only look good if can_queue is set to 1. I will investigate this case. > I'm having less happy results with a SATAPI DVD ... it looks like the > initial IDENTIFY goes across just fine, but that we stall on the other > SCSI commands ... I'm still investigating this one. I think we need set BLIST_NOREPORTLUN or some other flags (see scsi_devinfo.h) about new some ATAPI device.When calling scsi_report_lun_scan , it will bypass REPORT_LUNS command. -- Best Regards, Ke Wei -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
