On Thu, Jun 11, 2015 at 02:59:32AM +0800, Min-Hua Chen wrote: > In current design, the memblock.current_limit is set to > a section-aligned value in sanity_check_meminfo(). > > However, the section-aligned memblock may become non-section-aligned > after arm_memblock_init(). For example, the first section-aligned > memblock is 0x00000000-0x01000000 and sanity_check_meminfo sets > current_limit to 0x01000000. After arm_memblock_init, two memory blocks > [0x00c00000 - 0x00d00000] and [0x00ff0000 - 0x01000000] are reserved > by memblock_reserve() and make the original memory block > [0x00000000-0x01000000] becomes:
There isn't a problem with memblock_reserve(). That just marks the memory as reserved, it doesn't steal the memory from the lowmem mappings - in fact, it is still expected that reserved memory claimed in this way will be mapped. Somehow, I don't think this is what you're doing though, because you go on to describe a problem which can only happen if you steal memory after arm_memblock_init() has returned. Don't do this. There is a specific point in the boot sequence where you are permitted to steal memory, which is done inside arm_memblock_init(). Stealing outside of that is not permitted. arm_memblock_steal() is written to BUG_ON() if you attempt to do this outside of the permissible code paths. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
