Apple releases software fix for MacBook Pro slowdown
I had a serious slowdown issue on my 2010 MacBook Pro that took me a few years to figure out. It started after I spilled tea on it. The system appeared to function normally, but was very slow. When I ran top as root, it showed that kernel process was always using one core (>100% out of 200). I tried reinstalling the OS, changing options and upgrading, to no avail.Apparently, the OS does this to prevent thermal damage. It perceives that the CPU is overheating, so it sends one core into an idle loop to prevent it from doing real work.Finally, I took it to an Apple repair shop whose diagnostics determined the CPU thermal sensor was not working. That  didn’t immediately help. After much web searching, I found that a fix for this it was to completely disable the power management profile by deleting it. Now the machine works perfectly normally in terms of everything - heat, fans and performance. The machine seems to work identically to its original behavior, so I am puzzled at what function the power management profile performs.