* Russell King - ARM Linux <linux@xxxxxxxxxxxxxxx> [160622 01:32]: > When CONFIG_DEBUG_RODATA is enabled, we align the text, read-only data, > data, and so on to 1MB boundaries so that we can change the permissions > of the sections to enforce the properties of the various ELF segments. > This padding massively inflates the size of the run-time kernel image, > and can result in megabytes of wastage (if we're as little as one byte > into 1MB, we have to round up to the next megabyte.) Yes understood, and looks like we cannot make any assumptions about what the alignment might be. > The padding, being a string of zeros, is very compressable, and this > increases the compression ratio. > > The BSS is not included in the compressed image, but needs to be taken > account of when avoiding overwriting the DTB. > > > How about we check the size of RAM available, and if there is plenty > > of RAM we use a safe compression ratio of 8. If RAM is a problem, > > we could make the compression ratio smaller and warn about it. And > > we could also allow passing the compression ratio to kexec as an > > option. > > You do know that you can already pass the "size" of the kernel to be > reserved to kexec. --image-size. It's not documented in --help, but > it is there (which is another annoying thing about ARM kexec...) Oh ok that's nice. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
