On Fri, Mar 04, 2022 at 04:10:52PM +0100, Thomas Bogendoerfer wrote: > On Tue, Mar 01, 2022 at 12:28:58PM +0800, Tiezhu Yang wrote: > > According to Documentation/admin-guide/kernel-parameters.txt, > > the kernel command-line parameter mem= means "Force usage of > > a specific amount of memory", but when add "mem=3G" to the > > command-line, kernel boot hangs in sparse_init(). > > > > This commit is similar with the implementation of the other > > archs such as arm64, powerpc and riscv, refactor the function > > early_parse_mem() and then use memblock_enforce_memory_limit() > > to limit the memory size. > > > > With this patch, when add "mem=3G" to the command-line, the > > kernel boots successfully, we can see the following messages: > > unfortunately this patch would break platforms without memory detection, > which simply use mem=32M for memory configuration. Not sure how many > rely on this mechanism. If we can make sure nobody uses it, I'm fine > with your patch. maybe we could add a CONFIG option, which will be selected by platforms, which don't need/want this usermem thing. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]
