Daniel M Gessel wrote: > > > On 2024-08-06 11:47, Dan Ritter wrote: > > Daniel M Gessel wrote: > > > On 2024-08-06 00:31, Bill Bogstad wrote: > > > > We would have a whole lot fewer moles to whack if we changed our tools. > > > In some cases a 5% performance hit is huge - offering up "our programmers > > > make mistakes" as a justification is a non-starter. > > Remember that: > > > > - virtual machines impose a penalty of 1% or more -- worse when > > not optimally configured > > > > - the mitigations for various speculative execution and memory > > hammer attacks can impose 2-30% penalties depending on > > specific programs > > > > - changes between stable kernel versions can be +/- 15% in some > > cases > > > > All of those can already be cited as "our programmers make mistakes". > I honestly don't know how the first two address programmer mistakes; can you > explain?
The rise of virtual machines and containers is an admission of systemic failure: people gave up on managing dependencies in a sensible manner. Rather than have a deployment system which produces a working program plus libraries and configuration, these systems effectively ship a developer's laptop to the cloud. Mitigations for Spectre and Rowhammer are required because we persistently run other people's code on our hardware, or if you prefer, we keep running our code on other people's hardware and pretending that it's our hardware. > On the commercial OSs I've worked on, a 5% performance drop would be a > block-ship issue, depending on where it was seen. I don't know where you've worked, but I will bet a shiny nickel that 5% drops and 5% improvements happened in different sections on most major releases. -dsr- _______________________________________________ Discuss mailing list Discuss@driftwood.blu.org https://driftwood.blu.org/mailman/listinfo/discuss
