Safari 8.0 web process at 100% CPU every time I start Safari after resuming from sleep [closed]

Question

Whenever I start Safari 8.0 (on Yosemite 10.10) after resuming my Mac from sleep, it kicks off a web process which consumes 100% CPU and soon gets the fans on my MBA going:

What's strange is that it's always the same URL (http://www.saudecuf.pt/) which is a site I haven't visited for a very long time, certainly not since I upgraded to 10.10. I have no idea why it's picking up that URL. The only solution is to force quit that process and from then on Safari behaves normally until the next time I put my Mac to sleep.

Very frustrating.

BTW: the site is the site of a local private hospital, nothing special.

Answer 1

Sorry it's not a solution, but just to reassure you that you're not going mad: I have the exact same problem, different URL, but similarly old and unvisited - it's not even an open tab or within top-sites.

However, as well as peaking at 98% CPU usage, I also eventually get the red error notice in Activity Monitor 'Safari Web content (not responding)' and everything slows down - although Safari is mostly still usable.

I've tried disabling extensions and iCloud sync. Even restarting doesn't remove the old URL.

Answer 2

The only solutions I've found is to turn off the Favorites page. This seems to be related to the favorites page hanging up while trying to build itself.

Go into Safari Preferences. General tab.

Change the following. New windows open with: Empty Page New tab opens with: Empty Page

Solved it for me but annoying if you use the Favorites Page.

Answer 3

I had the same issue, start Safari, no open windows, at 100% of CPU.

The way to solve this was:

1. Close Safari
2. Go to ~/Library/Safari/
3. Remove all files from there
4. Open Safari, and wait for iCloud sync (all my bookmarks and stuff)

And done! My Safari was back to normal.

Answer 4

I've just had a similar issue with all open tabs jointly consuming 100% of the CPU, no matter how many or few I had open. Other processes were barely getting a look in, and Safari was still completely unusable. Closing & opening pages, relaunches and restarts didn't help.

I ran AdwareMedic. It found and facilitated removal of some scummy malware that had wormed its way in to Safari. This immediately resolved the problem.

Clearly these plugin writers are not the finest of software engineers – the thing would probably have gone unnoticed if it hadn't made my system and Safari hopelessly unresponsive.

I expect my son inadvertently installed it while trying to find interesting Minecraft plugins. Unfortunately the sites hosting them are stuffed full of malware downloads.

Worth a look, I reckon. Adwaremedic is donation ware.

Answer 5

When this happens, you can gather detailed logs and submit it to Apple for a bug fix or for specific support if you wish.

Open Activity Monitor, select Safari and then use the gear to "Run System Diagnostic" on the safari process.

This will make a comprehensive system snapshot that you can pick apart if you wish or keep it around until you have 10 instances and can then see if there's a pattern to the high CPU usage.