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<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - Background tabs should suspend or unload on macOS"
href="https://bugs.webkit.org/show_bug.cgi?id=162865#c5">Comment # 5</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - Background tabs should suspend or unload on macOS"
href="https://bugs.webkit.org/show_bug.cgi?id=162865">bug 162865</a>
from <span class="vcard"><a class="email" href="mailto:craig.hockenberry@gmail.com" title="Craig Hockenberry <craig.hockenberry@gmail.com>"> <span class="fn">Craig Hockenberry</span></a>
</span></b>
<pre>Now that you've armed me with a small bit of knowledge, I'm experimenting with Safari and the Activity Monitor :-)
When I load this page in Safari 10 (running on latest public Sierra), I see about 12-13% CPU usage:
<a href="https://stripe.com/docs">https://stripe.com/docs</a>
If I create another tab, and make it frontmost, the CPU usage drops down to well under 1% as expected. If I move the window to another space, I also see CPU usage go down. Awesome!
However, if I create another window and make it frontmost in the same space, the CPU usage for the previously opened window/tab doesn't go down.
Maybe the throttling needs to be applied to the frontmost tab of an inactive window, too. Personally, I tend to collect "ideas" in separate windows with multiple tabs. The Stripe site is me thinking about adding ApplePay to one of our commerce sites - it's the frontmost tab in the window because it's the last thing I looked at. The problem is that I have eight other windows in that space: only the frontmost one is collecting my current work.
The Stripe tab is churning away with no benefit to me, it's hidden by a bunch of other windows, and I'm still using Activity Monitor to find battery killers.
I hope this info is useful - I'm really glad you folks are thinking about this issue!</pre>
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