On January 20, 2019 8:10:03 AM PST, Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote: >On Sat, Jan 19, 2019 at 11:01:13PM -0800, hpa@xxxxxxxxx wrote: >> On January 19, 2019 2:36:06 AM PST, Greg KH ><gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >> >On Sat, Jan 19, 2019 at 02:28:00AM -0800, Christoph Hellwig wrote: >> >> This seems like a pretty horrible idea and waste of kernel memory. >> > >> >It's only a waste if you want it to be a waste, i.e. if you load the >> >kernel module. >> > >> >This really isn't any different from how /proc/config.gz works. >> > >> >> Just add support to kbuild to store a compressed archive in >initramfs >> >> and unpack it in the right place. >> > >> >I think the issue is that some devices do not use initramfs, or >switch >> >away from it after init happens or something like that. Joel has >all >> >of >> >the looney details that he can provide. >> > >> >thanks, >> > >> >greg k-h >> >> Yeah, well... but it is kind of a losing game... the more in-kernel >stuff there is the less smiley are things to actually be supported. > >It is better than nothing, and if this makes things a bit easier and >solves >real-world issues people have been having, and is optional, then I >don't see >why not. > >> Modularizing is it in some ways even crazier in the sense that at >that point you are relying on the filesystem containing the module, >which has to be loaded into the kernel by a root user. One could even >wonder if a better way to do this would be to have "make >modules_install" park an archive file – or even a directory as opposed >to a symlink – with this stuff in /lib/modules. We could even provide a >tmpfs shim which autoloads such an archive via the firmware loader; >this might even be generically useful, who knows. > >All this seems to assume where the modules are located. In Android, we >don't >have /lib/modules. This patch generically fits into the grand scheme >things >and I think is just better made a part of the kernel since it is not >that >huge once compressed, as Dan also pointed. The more complex, and the >more >assumptions we make, the less likely people writing tools will get it >right >and be able to easily use it. > >> >> Note also that initramfs contents can be built into the kernel. >Extracting such content into a single-instance tmpfs would again be a >possibility > >Such an approach would bloat the kernel image size though, which may >not work >for everyone. The module based approach, on the other hand, gives an >option >to the user to enable the feature, but not have it loaded into memory >or used >until it is really needed. > >thanks, > > - Joel Well, where are the modules? They must exist in the filesystem. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
