On Wed, Jun 3, 2009 at 23:11, David VomLehn (dvomlehn) wrote: > David Delaney has a proof-of-concept of an idea of his which was > presented at the last CELF, which is basically to put the kernel and > loadable kernel modules closely enough together that you can avoid the > use of long jumps. He sees a better than 1% improvement in performance, > which we've duplicated using a slightly different approach. This is nice > payback for little work and, though it doesn't help on all processors, > it helps on several. it would help on the Blackfin architecture. we compile all kernel modules with -mlong-call because of this issue. > The problem is: how do you allocate memory with the magical "close to > the kernel" attribute? We have something that adds a new ZONE_KERNEL > (this name has some problems, actually). It seems like a pretty good > solution if you look at zones as conceptually concentric usages, but > with the current zone implementation, each zone must be contiguous. So, > if we're talking about changing what zones are done, I'd like to throw > this into the pot. what do you do if the alloc fails ? return back to userspace with something like ENOMEM and have it retry with a module that was compiled with -mlong-call ? -mike -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
