On Thu, 2009-08-06 at 11:20 -0500, Mike Christie wrote: > On 08/05/2009 08:14 PM, Vasu Dev wrote: > > Bumps up queue_depth on fc_change_queue_depth call back with > > reason SCSI_QDEPTH_RAMP_UP. > > > > Sets up ramp up period in case current queue_depth is lower > > than max queue_depth in libfc. > > > > Signed-off-by: Vasu Dev<[email protected]> > > --- > > > > drivers/scsi/libfc/fc_fcp.c | 12 ++++++++++++ > > 1 files changed, 12 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c > > index 316767e..3502f80 100644 > > --- a/drivers/scsi/libfc/fc_fcp.c > > +++ b/drivers/scsi/libfc/fc_fcp.c > > @@ -129,6 +129,7 @@ static void fc_fcp_srr_error(struct fc_fcp_pkt *, > > struct fc_frame *); > > #define FC_MAX_RECOV_RETRY 3 > > > > #define FC_FCP_DFLT_QUEUE_DEPTH 32 > > +#define FC_FCP_RAMP_UP_PERIOD (120 * HZ) > > > > I think we want to make this common and setable. If we put a > ramp_up_period file in /sys/block/sda/device/ > > then we can set this for all scsi devices that support the feature. > Check out scsi_sysfs.c:scsi_sysfs_add_sdev for how to add sysfs files. >
Currently ramp_up_period will be mostly zero and will be set only if ramp up required which bit helps scsi-ml to completely skip ramp up code in case ramp_up_period value is zero. Given this period will be in seconds and ramp up code path is not lengthy when no ramp up required, so it will be okay to do always periodic ramp up based on setable sysfs variable. I'll add ramp_up_period to sysfs with default value set in common scsi code. Thanks for review comments. Vasu > > > /** > > * fc_fcp_pkt_alloc - allocation routine for scsi_pkt packet > > @@ -2054,9 +2055,20 @@ int fc_change_queue_depth(struct scsi_device *sdev, > > int qdepth, int reason) > > case SCSI_QDEPTH_QFULL: > > scsi_track_queue_full(sdev, qdepth); > > break; > > + case SCSI_QDEPTH_RAMP_UP: > > + if (qdepth + 1<= FC_FCP_DFLT_QUEUE_DEPTH) > > + scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), > > + qdepth + 1); > > + break; > > default: > > return -EOPNOTSUPP; > > } > > + > > + if (sdev->queue_depth< FC_FCP_DFLT_QUEUE_DEPTH) > > + sdev_set_rampup_period(sdev, FC_FCP_RAMP_UP_PERIOD); > > + else > > + sdev_set_rampup_period(sdev, 0); > > + > > return sdev->queue_depth; > > } > > EXPORT_SYMBOL(fc_change_queue_depth); > > > > _______________________________________________ > > devel mailing list > > [email protected] > > http://www.open-fcoe.org/mailman/listinfo/devel > > _______________________________________________ > devel mailing list > [email protected] > http://www.open-fcoe.org/mailman/listinfo/devel _______________________________________________ devel mailing list [email protected] http://www.open-fcoe.org/mailman/listinfo/devel
