why photolibraryd is consuming a lot of cpu

I have got 190 GB in my photos library, pictures plus videos. It stopped uploading to iCloud, where I have more than 500 GB free. I repaired the library in my iMac, following some instructions of the Apple Support pages. After that the process photolibraryd is getting 80% of CPU. For the moment it is like that 20 hours continuously. I am not doing other thing in the IMac. Should I let the IMac to finish? Does anybody knows how long can it take? What is the purpose of this consuming process?

Thanks.