Re: Bloated Struct Problem

[me22 <me22 dot ca at gmail dot com>]

2009/6/4 . . <pkejjy@gmail.com>:
> If so, that would be a bad performance decision in this
> multicore world, where memory footprint size matters much more than
> alignment, generally speaking.
>

But sharing of cache lines between unrelated things can be even worse.

And as you said, the point is to make the 64-bit ints properly aligned
when arrays of the type are used.  There are numerous architectures
which cannot read mis-aligned types, and those that can are usually
fairly slow at it -- especially when then end up straddling cache
lines, as an array of 17-byte structs certainly would, at some point.

There is, iirc, an __attribute__ that'll let you pack it, if you
insist.  Do you have profiler feedback that says it actually matters?