Thanks Mark, I 'll post a patch to raise the default host can queue value, I'm OK with his change! --Jack RE: [RFC PATCH 3/5] libsas: dynamic queue depth > > Good Stuff, 'cept I am worried about the host max queue depth of 128 on > the pm8001 driver resulting in starvation. I defer to Jack Wang's > judgement on that point (and will explore separately how we can increase > the host queue depth reliably on the pm8001). > > Consider this an Ack from me that has an interlock on Jack Wang's Ack > ... > > Sincerely -- Mark Salyzyn > > -----Original Message----- > From: Dan Williams [mailto:dan.j.williams@xxxxxxxxx] > Sent: Tuesday, September 20, 2011 6:11 PM > To: linux-ide@xxxxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx > Cc: Dave Jiang; Luben Tuikov; jgarzik@xxxxxxxxx; > JBottomley@xxxxxxxxxxxxx; Jack Wang; Xiangliang Yu; Mark Salyzyn; > Christoph Hellwig > Subject: [RFC PATCH 3/5] libsas: dynamic queue depth > > The queue-depth for libsas-attached devices initializes to 32 and can > only be increased manually via sysfs to a max of 64, while mpt2sas > attached devices initialize to 254 and dynamically float via the > midlayer ->change_queue_depth interface. > > No performance regression was observed with this change on the isci > driver. > > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Mark Salyzyn <msalyzyn@xxxxxxxxxxxxxx> > Cc: Xiangliang Yu <yuxiangl@xxxxxxxxxxx> > Cc: Jack Wang <jack_wang@xxxxxxxxx> > Cc: Mark Salyzyn <msalyzyn@xxxxxxxxxxxxxx> > Cc: Luben Tuikov <ltuikov@xxxxxxxxx> > Tested-by: Dave Jiang <dave.jiang@xxxxxxxxx> > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> > --- > drivers/scsi/libsas/sas_scsi_host.c | 39 > ++++++++++++++++------------------- > 1 files changed, 18 insertions(+), 21 deletions(-) > > diff --git a/drivers/scsi/libsas/sas_scsi_host.c > b/drivers/scsi/libsas/sas_scsi_host.c > index 4c6923c..fe08ef0 100644 > --- a/drivers/scsi/libsas/sas_scsi_host.c > +++ b/drivers/scsi/libsas/sas_scsi_host.c > @@ -784,8 +784,7 @@ int sas_target_alloc(struct scsi_target *starget) > return 0; > } > > -#define SAS_DEF_QD 32 > -#define SAS_MAX_QD 64 > +#define SAS_DEF_QD 256 > > int sas_slave_configure(struct scsi_device *scsi_dev) > { > ______________________________________________________________________ > This email may contain privileged or confidential information, which should > only be used for the purpose for which it was sent by Xyratex. No further rights > or licenses are granted to use such information. If you are not the intended > recipient of this message, please notify the sender by return and delete it. > You may not use, copy, disclose or rely on the information contained in it. > > Internet email is susceptible to data corruption, interception and > unauthorised amendment for which Xyratex does not accept liability. While we > have taken reasonable precautions to ensure that this email is free of viruses, > Xyratex does not accept liability for the presence of any computer viruses in > this email, nor for any losses caused as a result of viruses. > > Xyratex Technology Limited (03134912), Registered in England & Wales, > Registered Office, Langstone Road, Havant, Hampshire, PO9 1SA. > > The Xyratex group of companies also includes, Xyratex Ltd, registered in > Bermuda, Xyratex International Inc, registered in California, Xyratex > (Malaysia) Sdn Bhd registered in Malaysia, Xyratex Technology (Wuxi) Co Ltd > registered in The People's Republic of China and Xyratex Japan Limited > registered in Japan. > ______________________________________________________________________ > -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
