Hi, Playing with a recently acquired Promise SX8 card, we've found similar performance results to Matt's post to lkml a few months back at http://marc.theaimsgroup.com/?l=linux-kernel&m=110175890323356&w=2
It appears that the driver is only submitting one command at a time per port, which is at least one cause of the slowdowns. By raising CARM_MAX_Q from 1 to 3 in drivers/block/sx8.c (it was 3 in an earlier pre-merge incarnation of carmel.c), we're getting very notable speed improvements, with no side effects just yet. Knowing very little about what this change has actually done, I've a few questions: - Should this be considered dangerous? - Why was it taken from 3 to 1? - Is CARM_MAX_Q a number defined (or limited) by the hardware? Thanks in advance, Bernard. -- Bernard Blackham <bernard at blackham dot com dot au> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
