Dear Lucas De Marchi, In message <camow1v4zj8xva35b-txmuxmjutha0rmbxs3_c-tt75nbei1...@mail.gmail.com> you wrote: > > > Yocto uses this feature in a number of configurations; it creates an > > archive "/etc/dev.tar" on the first boot and, if this archive exists > > during the next boot, it gets extracted and most of the coldplug > > events are filtered. Only if the archive does not exist a full scan is > > performed. > > I didn't know this existed, but IMO is the wrong approach. If all you > want is a static /dev, you could have that partition already done, > without untar anything.
I don't want to argue about the approach. Probably each solution has it's own set of pros and cons. Note that "udev-cache" is not really static - it caches the information after first boot (or rather when the "/etc/dev.tar" file does not exist), so it can handle changing configurations, though in a not really convenient way. > > > == Scope == > > > # Implementation: 2 weeks > > > # Benchmark creation: 1 week > > > # Adapt to community feedback, tests and upstream: 2 weeks > > > > This appears to be way to high. All that needs to be done is using a > > Yocto based file system :-) > > A bit high because it's a different thing from what you are talking about ; > -) Well, in your proposal you said the purpose of this project was "to see how performance is improved by having such a cache." No matter what the deficiencies of the "udev-cache" approach may be, they are certainly good enough for such testing. It seems wasteful to me to invest 5 man-weeks of effort when it is not clear that the results are actually useful, and that they will be accepted by upstream. I think spending very few days upfront on measuring the performance benefits of the "udev-cache" approach makes a lot of sense, before investing man-weeks into any better approach. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: [email protected] A Chairman was as necessary to a Board planet as the zero was in mathematics, but being a zero had big disadvantages... - Terry Pratchett, _The Dark Side of the Sun_ _______________________________________________ Celinux-dev mailing list [email protected] https://lists.celinuxforum.org/mailman/listinfo/celinux-dev
