Andi Kleen wrote:
On those archs that take faults on unaligned accesses it's unlikely to
be in the noise. But we could (and should) stick a get_unaligned() in
the accessor functions.
Normally the compiler on such architectures generates special load/store code
for known unaligned types that does not actually fault, but just uses multiple
instructions. That is slower than a normal memory access, but still much
faster than a exception.
You only really get the full exception fault penalty when the compiler
cannot figure out at compile time that a given variable is unaligned.
But with packed it normally assumes that (I think)
Sounds reasonable. In which case the unaligned access issue I raised is
a red herring. So using uleb128 or not is down to whether the improved
packing efficiency is worth the increased complexity; it seems unlikely
that it is.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
