[23:36]  * [7] is observing weird I/O behavior with natty's 2.6.38-1209-omap4 kernel
[23:36] <[7]> when reading from a USB HDD, the relationship between read block sizes and throughput looks like this: http://paste.ubuntu.com/604616/
[23:36] <[7]> (the buffer cache has been flushed with hdparm -f between every measurement)
[23:36] <[7]> this HDD gets about 28MB/s on windows, and about 32MB/s without this weird foldback on my natty x86 desktop: http://paste.ubuntu.com/604619/
[23:36] <[7]> the same (but to a lesser extent) happens with slower USB storage devices as well: http://paste.ubuntu.com/604613/ (this thumbdrive gets 5MB/s on windows)
[23:36] <[7]> this also appears to affect SD card access, but also to a lesser extent: http://paste.ubuntu.com/604605/
[23:36] <[7]> does anyone have an idea what might be causing this, or how i could try to debug it?
[23:59] <ohsix> anyone know offhand what the practical difference between clear_page and clear_page_c is