After testing Process Priority Manager, Mozilla now ready to ship it with Firefox 69 on Windows. Firefox browser has the ability to set priority for its processes running on Windows, the company thought of giving priority to content processes running the tabs in the foreground than in background, background tabs running video and audio also treated as ‘active’.
Firefox Process Priority Manager
The Process Priority Manager feature behind the pref dom. has been turned on by default on Nightly quite some time for now, the company also tested feature on some users in the beta channel.
From the experiment results they ran with Process Priority manager enabled by default, they have not seen any negative impact on user engagement, page loading or tab switching time, but the feature isn’t bringing additional benefits either to the table, but Mozilla takes this as a win on resource usage side.
“We do know, however, that lowering background tab process priority allows the OS to priorities works in foreground tabs. so at the very least, this should be a resource usage win. So I think we should go ahead enable this and let it ride out.”
This says why this is a notable change “This enables a component (Process Priority Manager) that allows Firefox to give Windows hints on how best to prioritize CPU usage. Specifically, content Processes that only host tabs that are in the background will have their priorities lowered so that foreground processes get more processor time if they need it”
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