Pavel Machek <pavel@xxxxxxx> wrote: > Hi! > >> Short of a satisfying proposition regarding the questions raised, I just >> want to add two things that would be nice to solve in the future one way >> or another and should perhaps be taken into consideration from the >> beginning: >> >> 1. Disable polling completely when it isn't required: once the hd has >> spun down, there is no need to keep polling the sensors at all. Only >> when the first request requiring the hd to spin up arrives, the >> kernel needs to hold back for a short while to gather enough data >> from the sensors, so shock protection is up and running again. > > hdparm can already tell if disk is spinning or not. As userland is > polling, already, that may be enough? Yes, I know it *is* possible, I just think it may not be completely trivial to get it right. The only way I can think of, right now, is some sort of polling in the hdparm way, i.e. issuing a ATA_CMD_CHK_POWER from time to time. The question is how we are to decide when and how often we should poll for the current power state of the HD. > >> 2. Make shock protection interact nicely with suspend operations: >> currently, we are out of luck if anything should happen after >> processes have been frozen. This is particularly unfortunatel in the >> case of s2disk. > > I'd say that s2disk is similar to early boot... no protection there. Well, this is true for resume. However, I can't help thinking that we may do better than that until the disk spins down, particularly while writing the image to disk. Regards, Elias -- 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
