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
