Messages in this thread | | | Subject | Re: Problem with aacraid driver in 2.5.63-bk-latest | From | Mark Haverkamp <> | Date | 13 Mar 2003 07:42:13 -0800 |
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On Wed, 2003-03-12 at 17:06, Alan Cox wrote: > On Wed, 2003-03-12 at 23:55, Douglas Gilbert wrote: > > /* > > * Limit max queue depth on a single lun to 256 for now. Remember, > > * we allocate a struct scsi_command for each of these and keep it > > * around forever. Too deep of a depth just wastes memory. > > */ > > if(tags > 256) > > return; > > .... > > I can see the memory consideration. However the thing can really handle big > queues well. Possibly we should be setting the queue to 512 / somefunction(volumes) > though to avoid the worst case overcommit here >
Does the cmd_per_lun element of the Scsi_Host_Template structure serve more than one purpose? In scsi_alloc_sdev it is passed into scsi_adjust_queue_depth. In the aacraid case this is 512. Later the aacraid driver (in aac_slave_configure) sets the queue depth to either 128 for tagged or 1 if not.
Mark. -- Mark Haverkamp <markh@osdl.org>
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