> When the dest and the src do overlap and the memory area is large, memmove > of > x86_64 is very inefficient, and it led to bad performance, such as btrfs's > file > deletion performance. This patch improved the performance of memmove on > x86_64 > by using __memcpy_bwd() instead of byte copy when doing large memory area > copy > (len > 64). I still don't understand why you don't simply use a backwards string copy (with std) ? That should be much simpler and hopefully be as optimized for kernel copies on recent CPUs. -Andi -- 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
