This is basic testing.
Normally this is the mark of a bad software engineer, but attempting to blame the platform you’re on for your lack of testing takes it a to a new low.
Mistakes happen, admitting full incompetence that basic testing isn’t done is damning. This is not a good defense of Firefox nor Mozilla.
- we implement a feature, test it thoroughly for functional and non-functional requirements
- when we are happy, we release it
I don't see myself being responsible for a third party software company coming along years later and introducing a bug in code that injects itself between my software and the operating system that users of the software I wrote happens to install at some point.
As a software developer, I've had to workaround many many bugs in OSs, especially when dealing with updates to Android. It's just part of the job.
> With a standard Firefox configuration, the amount of calls to VirtualProtect is currently very high, and that is what explains the high CPU usage with Firefox. The information that the most impactful event originates from calls to VirtualProtect was forwarded to us by Microsoft, and I confirm it. In Firefox, disabling JIT makes MsMpEng.exe behave much more reasonably, as JIT engines are the source of the vast majority of calls to VirtualProtect.
> On Firefox's side, independently from the issue mentioned above, we should not consider that calls to VirtualProtect are cheap. We should look for opportunities to group multiple calls to VirtualProtect together, if possible. Even after the performance issue will be mitigated, each call to VirtualProtect will still trigger some amount of computation in MsMpEng.exe (or third-party AV software); the computation will just be more reasonably expensive.
> > the amount of calls to VirtualProtect is currently very high
Calling VirtualProtect is not writing to the temp folder. The VirtualProtect call is to change the permissions of the in-memory pages. It should be an inexpensive system call (other than the cost of TLB flushes and/or shootdowns).
It's very common knowledge that on Windows you will get terrible performance if you have many many small files.
I don't know why Microsoft doesn't fix that. Maybe they can't for compatibility reasons or something. But that's the way it is, and any software that wants to run well on Windows needs to deal with it by using fewer bigger files.
