To answer your query, yes. Ultimately, I believe the ml should be modified to view a user space modification to a lun's queue depth as an upper bound. I don't care, much, whether the system dynamically adjusts the queue depth or leaves it alone as long as it honors the value programmed via user space. Are you volunteering to do the work? :) How can I help? Thanks, Mike Giridhar Malavali wrote: > Hi Michael, > > Here are the patches.. > > http://marc.info/?a=119828370000006&r=1&w=2 . > http://marc.info/?l=linux-scsi&m=125201657106722&w=2 > > Thanks, > Giridhar.M.B > > > > On Sep 24, 2009, at 7:42 AM, Michael Reed wrote: > >> Hello, >> >> The purpose of the queue full tracking patch in qla2xxx is to >> keep the driver from changing a user space override of the queue >> depth back to what the driver believes is the "correct" value. >> >> The raid devices that we use have per raid controller queue depth >> limits and have at times demonstrated, uh, bad behavior when >> their queues are full for sustained periods of time. SGI needs >> to be able to set queue depth for a lun based upon access patterns >> and performance requirements of the entire cluster and know that >> it will be honored as an upper bound. >> >> Might you provide a pointer to the recently submitted patches? >> I haven't followed linux-scsi in a while.... I'll be quite >> happy to take a look. >> >> Thanks, >> Mike >> >> >> Giridhar Malavali wrote: >>> Hi Michael/James, >>> >>> Patches were submitted to move queue ramp up/down code recently to >>> scsi mid layer. With this change, I don't see a need for a module >>> parameter to disable queuefull tracking in qla2xxx driver. Andrew, >>> mentioned that this got introduced to avoid wobbling behavior on the >>> wire due to queue depth modifications. Just wanted to check whether >>> the same need to be done in scsi mid layer too. >>> >>> >>> Thanks, >>> Giridhar.M.B >>> >>> -- >>> 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 > -- 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
