On Fri, Apr 22, 2011 at 9:51 PM, Chris Ball <cjb@xxxxxxxxxx> wrote: > Hi, > > On Thu, Apr 21 2011, Andrei Warkentin wrote: >>>> Can you give me the manufacturing date? This is pretty interesting. >>>> >>>> You can see an improvement even if you do something like time block >>>> writes (O_DIRECT | O_SYNC, of course). But after all synthetic tests I >>>> measured the time it took to do 40000 SQLite insertions and saw >>>> something like 30% improvement. >>>> >>> >>> And you're trying this on SDHCI I presume, right? >> >> Is this on the same board as the other log you sent? Controller is >> SDHCI-PXA? If you give me /sys/block/mmcblk0/device/date, >> I'll investigate why this improvement isn't helping you out. > > Yeah, sdhci-pxa: > > [root@localhost olpc]# cat /sys/block/mmcblk0/device/date > 10/2010 > > Want to give me a benchmark script so that we can compare speeds > directly? > One more thing to check - is this an eMMC 4.3+ card? (you're going to have to plumb something in mmc.c to print it). Sandisk says improvement going to be seen only on 4.3+ cards. Sandisk releases different generation cards concurrently, and there is no way to tell from manfid/oemid/date/hwref/fwrev. Ugh. I'll send another email (in a bit) with test script and a patch to enable/disable cmd23 use at runtime so you can get better tests than across reboot. 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
