Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > Also, do Dave Chinner's ideas for indicating five I/O parameters want to be > > 32-bit numbers? Larger? Smaller? Can they be log2? > > Definitely 32 bit, IMO, as it's not uncommon to see optimal IO sizes > in the tens of megabytes on large, high bandwidth storage systems. > As for being log2 - that's just making it more complex to use and > making code ugly - we'd have to convert to log2 in kernel, then > convert back in every single application.... ilog2() in the kernel uses the CPU's bit-scan instruction if it has one and converting back is just a bitshift operator. But let's go with 32-bit fields for the moment. I presume we aren't worried about a driver that wants to do a 4GB transfer... David -- 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
