On Thu, Apr 14, 2011 at 6:18 PM, Chris Ball <cjb@xxxxxxxxxx> wrote: > > If we've seen a card that freaks out and loses significant bandwidth, that > would be a good reason to start with a whitelist. If all the data we have > suggests that it's performance-wise either a win or a no-op, that's a fine > reason to push it to mmc-next with a blacklist approach and change our > minds later if our knowledge gets updated. Does that help? > Yes, it does, thanks! Basically so far - (a) amazing boost for Sandisk eMMCs (b) synthetic tests showed no-op for Toshiba (a derivative of Arnd's flashbench, I'll put it up on GitHub as soon as my hands get to it), but more realistic test (via SQLite transactions on top of fs) showed slight deterioration. I'm bringing it up with the vendor to get a clear picture why and if they are doing anything to address it. (c) I am going to try to dig up some discrete MMCs (hard beasts to come by these days) and try with that. (d) I am going to dig up a few SDXCs and try them out. My current theory is that the CMD23 for multiblock should have no effect on the really braindead cards, and could have deterioration on cards that somehow optimize the CMD12 path (for example, the T eMMC optimize consecutive multiblock writes). At any rate, I'll decouple CMD23 support from multiblock CMD23 use... Yunpeng, I'm curious, what vendors did you have in mind when you suggested in your original email to use the CMD23 multiblock stuff? Thanks again, A -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
