Windows 10 security feature called Control Flow Guard (CFG) makes Chromium-based browsers run slower
The Vivaldi browser development team released a report saying that Windows 10 security feature called Control Flow Guard (CFG) severely slowed the performance of Chromium-based browsers. Test results based on the test suite show that the overall operating speed of Chromium-based browsers has dropped by a factor of three when this security feature is turned on.
When the development team found this problem, it also tried to replace the higher configuration computer, but the problem was successfully solved after the final switch to Windows7 system. Yngve Pettersen, developer and security expert at Vivaldi wrote,
“there were almost 11,000 tests run in separate processes in groups of 10, so the test suite would spawn about 1100 processes during one test run.
What I saw was that on Windows 7 this step took at most 2-3 milliseconds, while on Windows 10, it took at least 300 milliseconds, possibly as much as 600. And due to how the Chromium test code starts these processes, only one test process could be started at a time (and the end of test group handling also had to line up in the same line), so to start 8 processes would take at least 2.4 seconds, and only then could the results of a test group that usually used just 100 milliseconds to complete, be processed (that is, the first test group after running for 100 milliseconds had to wait at least 2300 milliseconds before its slot could start with the next group). That is a big reduction in performance.”
CreateProcess had O(n^2) performance for CFG data. Now it doesn't.
Timeline of this Windows performance bug:
April 15: Initial private report
April 21: Isolated repro and blog post
April 23: Fix built (flighting in a few weeks)https://t.co/PLsWMqeier— Bruce Dawson (@BruceDawson0xB) April 24, 2019
According to Microsoft, CFG is a feature specifically designed to prevent memory corruption vulnerabilities, by strictly restricting where applications can execute code. Chromium developer Bruce Dawson found that turning this feature off can solve the problem on Windows 10. This issue has been reported to Microsoft.
Although the test shows that performance is really degraded, this is only happening in a specific environment, most ordinary users will not have this problem using the browser. So users don’t have to do anything and need to wait for Microsoft’s cumulative update on May Patch Tuesday, and Microsoft can fix this bug completely.
Via: Vivaldi
