Re: ciss(4) write very slow w/o bbwc

[Kenneth R Westerback]

On Tue, May 29, 2012 at 03:48:02PM +0200, csszep wrote:
> Hi!
> 
> So i tested the ciss performance with Openbsd 5.1 and Netbsd 5.1.2 and
> the numbers are the same. :(
> 
> approx 13Mbyte/s write with dd if=/dev/zero of=/dev/rsd1c bs=1m count=500
> 
> But why Linux is four times faster (approx 40Mbyte/s)?

Dunno. But the diff below should apply the NetBSD 'fix' for the INQUIRY
command.

.... Ken


Dunno. But the diff below should apply the NetBSD 'fix' for the INQUIRY
command.

.... Ken


Index: ciss.c
===================================================================
RCS file: /cvs/src/sys/dev/ic/ciss.c,v
retrieving revision 1.67
diff -u -p -r1.67 ciss.c
--- ciss.c      10 Nov 2011 12:05:11 -0000      1.67
+++ ciss.c      29 May 2012 15:18:30 -0000
@@ -642,6 +642,14 @@ ciss_done(struct ciss_ccb *ccb)
 
        if (xs) {
                xs->resid = 0;
+               if (xs->cmd->opcode == INQUIRY) {
+                       struct scsi_inquiry_data *inq;
+                       inq = (struct scsi_inquiry_data *)xs->data;
+                       if ((inq->version & SID_ANSII) == 0 &&
+                            (inq->flags & SID_CmdQue) != 0) {
+                               inq->version |= 2;
+                        }
+               }
                scsi_done(xs);
        }