Andrew Paprocki wrote: > On 10/10/07, Tejun Heo <htejun@xxxxxxxxx> wrote: >> Maybe what should be done is to track sleep mode in libata and issue >> SRST automatically if a command is issued to a sleeping drive. I'll >> work on it. > > Another tidbit of info.. I just went through the pain of tracking down > everything in my system (system apps as well as my own code) > responsible for waking up sleeping drives. My end goal was to make > sure sleeping drives stayed asleep to reduce power consumption and > wear due to unnecessary spin-ups. I'm sure distros targeting laptops > or embedded systems that use live disks go through this pain > frequently. > > Would all SRST cmds sent from libata come from the ata_std_softreset() > call? Could something like SystemTap be used without modifying libata > to track all pids which cause that function to be called? If that > would work, it could be an easy way to do what I did manually. That > is, unless someone knows of an easier way that I'm overlooking.. :) I > might give that a try to see if it works well and document the result. All resets come from ata_eh_reset() and you can attach probes to it but the problem is that you can't identify the cause this way. libata EH thread would always be the issuing thread. I think the best way to track this is to use blktrace and look at which processes issue what requests. -- tejun - 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
