Hi Mingming, mmc <m...@linux.vnet.ibm.com> writes: > On 2019-06-21 00:05, Nathan Lynch wrote: >> So return -EAGAIN instead of -EBUSY when this race is >> encountered. Additionally: logging this event is still appropriate but >> use pr_info instead of pr_err; and remove use of unlikely() while here >> as this is not a hot path at all. > > Looks good, since it's not a hot path anyway, so unlikely() should > benefit from optimize compiler path, and should stay. No?
The latency of this path in rtas_ibm_suspend_me() in the best case is around 2-3 seconds. So I think not -- this is such a heavyweight and relatively seldom-executed path that the unlikely() cannot yield any discernible performance benefit, and its presence imposes a readability cost.
