Hello, Gwendal. On Mon, Jan 13, 2014 at 04:36:52PM -0800, Gwendal Grignou wrote: > Won't this patch defeat staggered spinup at resume? If you have a jbod > with a smallish power supply, with a 12V rail designed for the steady > state and 1 or 2 devices spinning up at once, you may be in trouble > when all the disks will want to spinup in same second.
Yeah, I think it would. We never fully solved the staggered spinup problem and it probably is too late to invest into proper mechanism for that. I think an easy workaround would be, say, have a kernel param which limits the max number of concurrent async wakeups and set the value to something reasonable - say, 2, which should give us most of benefits of async wakeup in vast majority of cases while avoiding blowing up PSUs on larger setups. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
