From: Rob Gardner <rob.gardner@xxxxxxxxxx> Date: Fri, 25 Dec 2015 22:02:43 -0700 > Also, in the code we submitted, there was an optimization in which > %asi is read, and then only set to ASI_AIUS if necessary. This > drastically reduces the number of writes to the %asi register since > most of the time %asi will contain ASI_AIUS. This seems like a > reasonable optimization, since this function may be called thousands > of times per second on every cpu. I noticed the optimization. If this was happening for every memcpy call, I'd say it's worth it. But it's happening once for a series of memcpy/copy_from_user_inatomic() calls so I'd say it's not really worth it. So unless you can show me how the current version fails, I'm keeping it as-is because either we should consistently use set_fs/get_fs in C code rather than open coded inline asm, or we should create a well documented set of helper functions for this specific situation and _ALSO_ use it elsewhere where the same problems exist such as some of the uses of set_fs/get_fs in process_64.c -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
