On Wed, Mar 07, 2012 at 08:10:00AM +0100, Lukas Czerner wrote: > > Ok, if there is a plan to implement that, I am fine with dropping th > patches. But since this optimization would be helpful for discard, we > can introduce BLOCK_DISCARDED/UNPROVISIONED flag maybe ? Which would be > sen only after discard and cleared with the first allocation ? Heh, great minds think alike. I was thinking about a the possibility of having a BLOCK_DISCARDED flag this morning, with exactly the semantics that you are suggesting. There may be devices in the future that have fast trims which will prefer to always get the duplicate trim requests, but there is no question there are a lot of crappy devices out there right now where trims are extremely expensive, so that seems fair. Something else to think about for the future, for battery driven devices (such as handsets) automatically sending tirm commands might not be a good idea when the device is sleeping/has the screen turned off. Given that we don't have an easy way of determining whether or not the device is in a low powered state (ideally we only send the trims right after work has been queued to the device, so it's woken up already, but when there isn't anything else that needs to be sent to the device). - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
