Sergei Shtylyov wrote:
Do you really think that the transfers having lengths non-divisible by 4 make any *significant* percentage even on the ATAPI devices? I think it's you who is really wrong.
The answer depends on workload. Though rare, workloads do exist that involve a lot of oddball querying via weird, vendor-specific SCSI[-ish] commands.
Moreover, the likelihood and cost of a branch mispredict are both low in this case, IMO.
Or a more human version of the rule: if you have to have a long email thread about unlikely() placement, it is best just to avoid using unlikely() in that case at all. Branch prediction units in modern CPUs are damned good anyways, and there is always the likelihood that a human-placed unlikely() becomes wrong in the future.
Plus the code is more readable without unlikely(), IMO. Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
